Ax-15 to A833 swap

[Iron and Resin]

Hey everyone, I need your guys help and expertise. Right now my 73 duster has an AX-15 five speed out of a 93’ dodge dakota and I recently bought a rebuilt a833. My car currently has an LA318 but I am going to put a 340 in the car down road. All the trans came with was the flywheel and the bell housing. My questions are:

1) What will I need in order to put this in my car?

2) Would you guys recommend waiting until the 340 is ready to go in and do the new engine and transmission at the same time, or can I go ahead and swap the transmission now with the 318 still in the car? I would prefer to do the latter if possible since I don’t like the AX15 at all.

Here is a list of what I think I need, and their price:

Non console shifter with good chrome, includes mechanism and linkage with tabs, 399


Pedal push rod, 55


Z bar for V8, 79


Inner Fender reinforcement bracket for manual trans, 35


Manual transmission crossmember, 125


Wiring for manual trans to operate backup lights, 35


Shifter adapter plate, with bolts, 55

Is there some of this stuff that I can forgo, and am I missing anything? Thank you in advance!

 

[Professor Fate]

Hey everyone, I need your guys help and expertise. Right now my 73 duster has an AX-15 five speed out of a 93’ dodge dakota and I recently bought a rebuilt a833. My car currently has an LA318 but I am going to put a 340 in the car down road. All the trans came with was the flywheel and the bell housing. My questions are:

1) What will I need in order to put this in my car?

2) Would you guys recommend waiting until the 340 is ready to go in and do the new engine and transmission at the same time, or can I go ahead and swap the transmission now with the 318 still in the car? I would prefer to do the latter if possible since I don’t like the AX15 at all.

Here is a list of what I think I need, and their price:

Non console shifter with good chrome, includes mechanism and linkage with tabs, 399


Pedal push rod, 55


Z bar for V8, 79


Inner Fender reinforcement bracket for manual trans, 35


Manual transmission crossmember, 125


Wiring for manual trans to operate backup lights, 35


Shifter adapter plate, with bolts, 55

Is there some of this stuff that I can forgo, and am I missing anything? Thank you in advance!

Z bar to clutch fork rod and retaining clips, pivot bushings, return spring, over center spring, transmission tunnel hump, shift boot and trim ring, throwout bearing and arm, dust boots at firewall and bellhousing, shift knob, front carpeting for manual transmission, clutch plate and pressure plate, slip yoke and driveshaft, speedometer drive gear, transmission mount, etc. Lots more I'm not thinking of right now.
Crossmember will depend on how the current one was modified to accommodate the AX-15 (BTW, there is NO difference between a manual or automatic transmission crossmember). Make sure your flywheel is a neutral balanced unit- not a late '72-'73 340 external balance piece or one from a 360- neither will work with your 318 or 340 (assuming your 340 is a '68-early '72 engine) which are all internally (neutral) balanced.
Seriously, contact Brewer's for a parts quote (and tell them EXACTLY what you've got and what you're doing).
1963-1976 A-BODY COMPLETE 4-SPEED CONVERSION PACKAGE - Mopar A833 4-Speed Transmission & Component Specialists

 

[RAT ROD AL]

Not sure if the trans xmember is different. I thought they were all the same.

 

[67Dart273]

I doubt whatever was ?fabricated? for the AX 15 fits the A833, but guess you never know

 

[Iron and Resin]

Awesome thanks guys. I’ll give brewers a call.

 

[AJ/FormS]

May I ask what it was that you didn't like about the Ax15?
Was it the distant 3rd gear ?
or the Deep low?
Or the hard to gear-for Second gear?

Yur gonna like the A833, Especially if its a Commando.

 

[Iron and Resin]

May I ask what it was that you didn't like about the Ax15?
Was it the distant 3rd gear ?
or the Deep low?
Or the hard to gear-for Second gear?

Yur gonna like the A833, Especially if its a Commando.

First gear is way too low, it has a hydraulic clutch and my clutch pedal geometry is set up for mechanical clutch so it doesn’t engage properly, and I don’t think it’ll hold up to the 340 I’m going to put in the car eventually

 

[AJ/FormS]

My experience with a manual transmission for street performance, is to put Second gear where you want it, by selection of an appropriate rear gear, then let the rest be whatever,
The reason is this;
>No matter what transmission your streeter has; First gear will nearly always be too low
>And Third gear will always top out at too high a roadspeed.
> But Second is where all the Street action is. So if you can gear the vehicle to run out of power on the downside of the power curve, at or near 60 mph, that will be about as perfect as it gets.
For me, depending on what cam was in it, that was about 5900, in 1.92 Second, with 4.10s, for 60mph.
Which means 30mph was half that, 2950.
That makes a powerband requirement of 2950rpm ..... so I chose a Hi-pressure 360 to punch up the bottom end.

Eventually, I figured out that my engine had a long flat power curve at the top, and she would pull even to 7000 in Second, so I regeared it with 4.88s, and now it was doing 3500@30mph Badaboom.
and with 4.88s, the slowest I could drive it was 3.4mph @550rpm in gear and pullitself.
But, on the hiway, 65 was a tic under 4000, so I bought an overdrive, for 65=3100

Eventually, that got old, and I began to think of a better way.
Eventually I figured out that my car liked a Second Gear of 6.5 to 6.80, expressed as a roadgear.
So, If I was running a 2.66 low box with a 1.92 Second, I needed a rear gear of 3.39, which I rounded to 3.55, for 30= 2550, 65=2870 in 4th
But if I was running the overdrive box with 1.67 Second, I needed a rear gear of 3.91s for 30=2440, 65=2310 in 4th. I ran this for a few years.
But, like you, eventually iI found the 3.09 x 3.91= 12.08 first roadgear to be too deep. I had a shed full of pumpkins so I began to look for a sweet low gear ratio, and ended up at about 11/1 ..So then I had the first two gears sorted, at 11 and 6.8, which only come in one Mopar combo, namely, the Commando, and 3.55s. So I called Passon Performance, who supplied a real nice gearset. and to that I added the GVod, so
Today, and since 2004, my ratios are .......... 3.09-1.93-1.40-1.00-.78od
With the 3.55s, the roadgears are ............... 10.97-6.82-4.97-3.55-2.77
Compare the closest AX15, with 2.94s at ... 11.26-6.85-4.23-2.94-2.32

Well looky-looky, the first three gears line up pretty good; but to pull a 2.32 for 65=1880, with any kind of fuel economy, is gonna take a pretty small cam, but hang on; in Direct, 65=2380, which would be perfect for a 340., leaving 2.32gear for 2380=82 mph which is looking pretty good.

In one of my combos, I ran 65=2240 in GVoverdrive, 82= 2010 in Second over. My small-cammed 367Hi-pressure, got fabulous fuel-economy.
Now, as to your standard box A833, the ratios are 2.66-1.92-1.40-1.00
And I'll bet you are gonna need at least 3.55s to get off the line half decent, so lets see how that compares. I get ... 9.44-6.82-4.97-3.55
and 65= 2870. I was no fan of that, so I cruised at 56= 2480, until I got the GVod, when 65=2240. Now I'm a happy happy guy.


But I'll tell ya, a nice hi-compression 318 would love that AX15 with 2.94s ; 11.26-6.85-4.23-2.94-2.32, 65=1880.

 

[Iron and Resin]

My experience with a manual transmission for street performance, is to put Second gear where you want it, by selection of an appropriate rear gear, then let the rest be whatever,
The reason is this;
>No matter what transmission your streeter has; First gear will nearly always be too low
>And Third gear will always top out at too high a roadspeed.
> But Second is where all the Street action is. So if you can gear the vehicle to run out of power on the downside of the power curve, at or near 60 mph, that will be about as perfect as it gets.
For me, depending on what cam was in it, that was about 5900, in 1.92 Second, with 4.10s, for 60mph.
Which means 30mph was half that, 2950.
That makes a powerband requirement of 2950rpm ..... so I chose a Hi-pressure 360 to punch up the bottom end.

Eventually, I figured out that my engine had a long flat power curve at the top, and she would pull even to 7000 in Second, so I regeared it with 4.88s, and now it was doing 3500@30mph Badaboom.
and with 4.88s, the slowest I could drive it was 3.4mph @550rpm in gear and pullitself.
But, on the hiway, 65 was a tic under 4000, so I bought an overdrive, for 65=3100

Eventually, that got old, and I began to think of a better way.
Eventually I figured out that my car liked a Second Gear of 6.5 to 6.80, expressed as a roadgear.
So, If I was running a 2.66 low box with a 1.92 Second, I needed a rear gear of 3.39, which I rounded to 3.55, for 30= 2550, 65=2870 in 4th
But if I was running the overdrive box with 1.67 Second, I needed a rear gear of 3.91s for 30=2440, 65=2310 in 4th. I ran this for a few years.
But, like you, eventually iI found the 3.09 x 3.91= 12.08 first roadgear to be too deep. I had a shed full of pumpkins so I began to look for a sweet low gear ratio, and ended up at about 11/1 ..So then I had the first two gears sorted, at 11 and 6.8, which only come in one Mopar combo, namely, the Commando, and 3.55s. So I called Passon Performance, who supplied a real nice gearset. and to that I added the GVod, so
Today, and since 2004, my ratios are .......... 3.09-1.93-1.40-1.00-.78od
With the 3.55s, the roadgears are ............... 10.97-6.82-4.97-3.55-2.77
Compare the closest AX15, with 2.94s at ... 11.26-6.85-4.23-2.94-2.32

Well looky-looky, the first three gears line up pretty good; but to pull a 2.32 for 65=1880, with any kind of fuel economy, is gonna take a pretty small cam, but hang on; in Direct, 65=2380, which would be perfect for a 340., leaving 2.32gear for 2380=82 mph which is looking pretty good.

In one of my combos, I ran 65=2240 in GVoverdrive, 82= 2010 in Second over. My small-cammed 367Hi-pressure, got fabulous fuel-economy.
Now, as to your standard box A833, the ratios are 2.66-1.92-1.40-1.00
And I'll bet you are gonna need at least 3.55s to get off the line half decent, so lets see how that compares. I get ... 9.44-6.82-4.97-3.55
and 65= 2870. I was no fan of that, so I cruised at 56= 2480, until I got the GVod, when 65=2240. Now I'm a happy happy guy.


But I'll tell ya, a nice hi-compression 318 would love that AX15 with 2.94s ; 11.26-6.85-4.23-2.94-2.32, 65=1880.

Hmm, forgive me because I’m no expert with gear ratios and transmission stuff so I’m having a hard time really understanding a lot of that, but what I’m getting is that you think the ax15 is actually not a bad setup for my current 318 or the 340 down the road? How would I go about fixing the clutch pedal geometry? Thank you

 

[AJ/FormS]

what I’m getting is that you think the ax15 is actually not a bad setup for my current 318

If you have the ratios that I have on file, then it's a GREAT set of ratios for a 318. On file I have; ... 3.83-2.33-1.44-1.00-.79od
But;
IMO there are limitations;
After 55 years of driving manual transmission Mopars, I am finally happy with the ratios that I ended up at, which are;
3.09-1.92-1.40-1.00-.78od.
IMO, there is no better set for an A-body street machine.
the splits are .62-.73-.72-.78, which means that whatever you rev it to, on the shift, the Rpm will drop TO these percents. So, if you typically out-shift First at 3200, Second will come in at 3200 x .62= 1980; which means, your 318 has to have at least a little power at that 1980rpm.
Conversely, if your 318 doesn't wake up until 2400, then you will want to outshift First at 2400/.62=3870
So, IMO, the ratios that I have, with a hi-pressure 360 are perfect with a 3.55 rear gear. And I have run this gearset with a 318, for several winters, with lesser rear gears, even down to 2.76s, with good results. I am confident enough to say that if you had these ratios, you would never want for anything else.
Now then:
Back to the AX15
This gearset is NOT better than the Commando/GVod; But is a very close second choice.
The splits are .61-.62-.69-.79,
Which are pretty close to the Commando, except for Second gear. This means that for performance in a streeter, your engine is gonna need some grunt at the bottom of Second OR ...... OR, you would need to carry first gear out a we bit higher.
To get the Low-rpm Grunt, you need cylinder pressure.
Option 2, works just as good, you just can't show off quite as good.
Now we get into the heart of it;
To compare to the Commando ROAD-gears of
10.97-6.82-4.97-3.55-2.77
The AX wants the following rear gears
In First; .... 2.86
in Second; 2.93
in Third: ....3.45
in Fourth; . 3.55
in Fifth; .... 3.50
So, what do you do?
Well for me, Second gear rules, so I'm going with 2.94s.....
But for the 318, I'd go up to 3.23 for a bit more second gear punch. This will bring the rest of the gears down a bit, but for a streeter, that's no big deal, cuz top of third with 3.23s say 5000 rpm, would be 86mph.
In town, granny shifting will be just fine, but for excited driving, NOT WOT, you'll have to find a sweet spot just a bit further up the rpm band.
But look at the AX15 split from third gear on........ they are ideal for a modest powered 318.


To help you understand gearing, Here's what is happening;
every gear, multiplies your crankshaft torque by whatever the ratio is, which then gets multiplied by the rear gear.
So, in the case of the AX15 First gear of 3.83, and say you had 3.91s in the back, and say your 318 makes 250 ftlbs at 2000 rpm.
As far as the tires are concerned, at WOT, they're gonna see;
250 x 3.83 x 3.91= 3744 ftlbs, a very significant number.
Lets compare that to a 340 with the T/A box and 3.23s, Suppose the 340 make 300ftlbs at 2000rpm. The Tires, at WOT, are gonna see
300 x 2.47 x 3.23=2393 ftlbs.
Guess which combo is getting out first.
Ok I admit, not many guys use the 2.47 box, and not many use 3.23s, so lets pump it up a bit to
300 x 2.66 x 3.73= 2976, If you have the ratios that I have on file, then it's a GREAT set of ratios for a 318. On file I have; ... 3.83-2.33-1.44-1.00-.79od
But;
IMO there are limitations;
After 55 years of driving manual transmission Mopars, I am finally happy with the ratios that I ended up at, which are;
3.09-1.92-1.40-1.00-.78od.
IMO, there is no better set for an A-body street machine.
the splits are .62-.73-.72-.78, which means that whatever you rev it to, on the shift, the Rpm will drop TO these percents. So, if you typically out-shift First at 3200, Second will come in at 3200 x .62= 1980; which means, your 318 has to have at least a little power at that 1980rpm.
Conversely, if your 318 doesn't wake up until 2400, then you will want to outshift First at 2400/.62=3870
So, IMO, the ratios that I have, with a hi-pressure 360 are perfect with a 3.55 rear gear. And I have run this gearset with a 318, for several winters, with lesser rear gears, even down to 2.76s, with good results. I am confident enough to say that if you had these ratios, you would never want for anything else.
Now then:
Back to the AX15
This gearset is NOT better than the Commando/GVod; But is a very close second choice.
The splits are .61-.62-.69-.79,
Which are pretty close to the Commando, except for Second gear. This means that for performance in a streeter, your engine is gonna need some grunt at the bottom of Second OR ...... OR, you would need to carry first gear out a we bit higher.
To get the Low-rpm Grunt, you need cylinder pressure.
Option 2, works just as good, you just can't show off quite as good.
Now we get into the heart of it;
To compare to the Commando ROAD-gears of
10.97-6.82-4.97-3.55-2.77
The AX wants the following rear gears
In First; .... 2.86
in Second; 2.93
in Third: ....3.45
in Fourth; . 3.55
in Fifth; .... 3.50
So, what do you do?
Well for me, Second gear rules, so I'm going with 2.94s.....
But for the 318, I'd go up to 3.23 for a bit more second gear punch. This will bring the rest of the gears down a bit, but for a streeter, that's no big deal, cuz top of third with 3.23s say 5000 rpm, would be 86mph.
In town, granny shifting will be just fine, but for excited driving, NOT WOT, you'll have to find a sweet spot just a bit further up the rpm band.
But look at the AX15 split from third gear on........ they are ideal for a modest powered 318.


To help you understand gearing, Here's what is happening;
every gear, multiplies your crankshaft torque by whatever the ratio is, which then gets multiplied by the rear gear.
So, in the case of the AX15 First gear of 3.83, and say you had 3.91s in the back, and say your 318 makes 250 ftlbs at 2000 rpm.
As far as the tires are concerned, at WOT, they're gonna see;
250 x 3.83 x 3.91= 3744 ftlbs, a very significant number.
Lets compare that to a 340 with the T/A box and 3.23s, Suppose the 340 make 300ftlbs at 2000rpm. The Tires, at WOT, are gonna see
300 x 2.47 x 3.23=2393 ftlbs.
Guess which combo is getting out first.
Ok I admit, not many guys use the 2.47 box, and not many use 3.23s, so lets pump it up a bit to
300 x 2.66 x 3.73= 2976, Guess whos moving out faster.
Ok so maybe your 318 cannot muster 250 ftlbs.
To equal the 2976 of the 340, your 318 would need to have
2976/(3.83 x 3.73)= 208ftlbs which IMO would be pretty sick.
But suppose I guessed the 340 wrong. To equal 3744, it would need to be making ; 3744/(2.66 x 3.73)= 377ftlbs at 2000rpm. In a streeter, I can't see that at 2000rpm.
Furthermore, your first gear of say 3.83 x 3.23=12.37 is pretty deep, and to run that with a Mopar 2.66 would require a rear-gear of 4.65 which would be highly unusual for anybody to run. Therefore, of all the Mopar 4-speeders that you are ever likely to meet, not even one of them can compare to your first gear. Well, maybe one.
As for second with the AX15, 2.33x3.23= 7.52,
and with the Mopar is 1.92 x 3.55 =6.82 what most guys will run so you are 10% greater , so your engine can be 10% less powerful, and you guys might run neck and neck.

By third gear, your AX15, 1.44gear is about the same as the Mopar 1.40 but the 340 car is running 3.55s to your 3.23s , so, sooner or later, the 340 car is gonna leave you behind.

So that's how that works.
Finally, the combination of overdrive and 3.23s makes for a very low cruise ratio of 2.55, and 65=2060, which is about as low as you can go with a 318, and still feed it optimal ignition timing, with the factory systems. Any slower rpm, and yur gonna need a computer, to better your fuel-economy. So that means, a little more rpm will not affect your economy much. in fact, 2400 is about when it begins to drop off, which is why I run 2240. To run 2240 with the AX15 would require a rear gear of 3.55s, so, IMO, you wouldn't run any more than that, cuz of what happens in First gear If you already have these installed, I would leave them in there with the AX15. But if you have anything bigger, I would swap them out for not more than 3.23s unless you already had nothing but the 3.55s under the bench.

 

[AJ/FormS]

How would I go about fixing the clutch pedal geometry? Thank you

well that there is the 64 dollar question since IDK what you have or what the problem is, lol. But lotsa guys run the hydros (I never have) with good success, so, there must be a solution.

 

[Iron and Resin]

If you have the ratios that I have on file, then it's a GREAT set of ratios for a 318. On file I have; ... 3.83-2.33-1.44-1.00-.79od
But;
IMO there are limitations;
After 55 years of driving manual transmission Mopars, I am finally happy with the ratios that I ended up at, which are;
3.09-1.92-1.40-1.00-.78od.
IMO, there is no better set for an A-body street machine.
the splits are .62-.73-.72-.78, which means that whatever you rev it to, on the shift, the Rpm will drop TO these percents. So, if you typically out-shift First at 3200, Second will come in at 3200 x .62= 1980; which means, your 318 has to have at least a little power at that 1980rpm.
Conversely, if your 318 doesn't wake up until 2400, then you will want to outshift First at 2400/.62=3870
So, IMO, the ratios that I have, with a hi-pressure 360 are perfect with a 3.55 rear gear. And I have run this gearset with a 318, for several winters, with lesser rear gears, even down to 2.76s, with good results. I am confident enough to say that if you had these ratios, you would never want for anything else.
Now then:
Back to the AX15
This gearset is NOT better than the Commando/GVod; But is a very close second choice.
The splits are .61-.62-.69-.79,
Which are pretty close to the Commando, except for Second gear. This means that for performance in a streeter, your engine is gonna need some grunt at the bottom of Second OR ...... OR, you would need to carry first gear out a we bit higher.
To get the Low-rpm Grunt, you need cylinder pressure.
Option 2, works just as good, you just can't show off quite as good.
Now we get into the heart of it;
To compare to the Commando ROAD-gears of
10.97-6.82-4.97-3.55-2.77
The AX wants the following rear gears
In First; .... 2.86
in Second; 2.93
in Third: ....3.45
in Fourth; . 3.55
in Fifth; .... 3.50
So, what do you do?
Well for me, Second gear rules, so I'm going with 2.94s.....
But for the 318, I'd go up to 3.23 for a bit more second gear punch. This will bring the rest of the gears down a bit, but for a streeter, that's no big deal, cuz top of third with 3.23s say 5000 rpm, would be 86mph.
In town, granny shifting will be just fine, but for excited driving, NOT WOT, you'll have to find a sweet spot just a bit further up the rpm band.
But look at the AX15 split from third gear on........ they are ideal for a modest powered 318.


To help you understand gearing, Here's what is happening;
every gear, multiplies your crankshaft torque by whatever the ratio is, which then gets multiplied by the rear gear.
So, in the case of the AX15 First gear of 3.83, and say you had 3.91s in the back, and say your 318 makes 250 ftlbs at 2000 rpm.
As far as the tires are concerned, at WOT, they're gonna see;
250 x 3.83 x 3.91= 3744 ftlbs, a very significant number.
Lets compare that to a 340 with the T/A box and 3.23s, Suppose the 340 make 300ftlbs at 2000rpm. The Tires, at WOT, are gonna see
300 x 2.47 x 3.23=2393 ftlbs.
Guess which combo is getting out first.
Ok I admit, not many guys use the 2.47 box, and not many use 3.23s, so lets pump it up a bit to
300 x 2.66 x 3.73= 2976, If you have the ratios that I have on file, then it's a GREAT set of ratios for a 318. On file I have; ... 3.83-2.33-1.44-1.00-.79od
But;
IMO there are limitations;
After 55 years of driving manual transmission Mopars, I am finally happy with the ratios that I ended up at, which are;
3.09-1.92-1.40-1.00-.78od.
IMO, there is no better set for an A-body street machine.
the splits are .62-.73-.72-.78, which means that whatever you rev it to, on the shift, the Rpm will drop TO these percents. So, if you typically out-shift First at 3200, Second will come in at 3200 x .62= 1980; which means, your 318 has to have at least a little power at that 1980rpm.
Conversely, if your 318 doesn't wake up until 2400, then you will want to outshift First at 2400/.62=3870
So, IMO, the ratios that I have, with a hi-pressure 360 are perfect with a 3.55 rear gear. And I have run this gearset with a 318, for several winters, with lesser rear gears, even down to 2.76s, with good results. I am confident enough to say that if you had these ratios, you would never want for anything else.
Now then:
Back to the AX15
This gearset is NOT better than the Commando/GVod; But is a very close second choice.
The splits are .61-.62-.69-.79,
Which are pretty close to the Commando, except for Second gear. This means that for performance in a streeter, your engine is gonna need some grunt at the bottom of Second OR ...... OR, you would need to carry first gear out a we bit higher.
To get the Low-rpm Grunt, you need cylinder pressure.
Option 2, works just as good, you just can't show off quite as good.
Now we get into the heart of it;
To compare to the Commando ROAD-gears of
10.97-6.82-4.97-3.55-2.77
The AX wants the following rear gears
In First; .... 2.86
in Second; 2.93
in Third: ....3.45
in Fourth; . 3.55
in Fifth; .... 3.50
So, what do you do?
Well for me, Second gear rules, so I'm going with 2.94s.....
But for the 318, I'd go up to 3.23 for a bit more second gear punch. This will bring the rest of the gears down a bit, but for a streeter, that's no big deal, cuz top of third with 3.23s say 5000 rpm, would be 86mph.
In town, granny shifting will be just fine, but for excited driving, NOT WOT, you'll have to find a sweet spot just a bit further up the rpm band.
But look at the AX15 split from third gear on........ they are ideal for a modest powered 318.


To help you understand gearing, Here's what is happening;
every gear, multiplies your crankshaft torque by whatever the ratio is, which then gets multiplied by the rear gear.
So, in the case of the AX15 First gear of 3.83, and say you had 3.91s in the back, and say your 318 makes 250 ftlbs at 2000 rpm.
As far as the tires are concerned, at WOT, they're gonna see;
250 x 3.83 x 3.91= 3744 ftlbs, a very significant number.
Lets compare that to a 340 with the T/A box and 3.23s, Suppose the 340 make 300ftlbs at 2000rpm. The Tires, at WOT, are gonna see
300 x 2.47 x 3.23=2393 ftlbs.
Guess which combo is getting out first.
Ok I admit, not many guys use the 2.47 box, and not many use 3.23s, so lets pump it up a bit to
300 x 2.66 x 3.73= 2976, Guess whos moving out faster.
Ok so maybe your 318 cannot muster 250 ftlbs.
To equal the 2976 of the 340, your 318 would need to have
2976/(3.83 x 3.73)= 208ftlbs which IMO would be pretty sick.
But suppose I guessed the 340 wrong. To equal 3744, it would need to be making ; 3744/(2.66 x 3.73)= 377ftlbs at 2000rpm. In a streeter, I can't see that at 2000rpm.
Furthermore, your first gear of say 3.83 x 3.23=12.37 is pretty deep, and to run that with a Mopar 2.66 would require a rear-gear of 4.65 which would be highly unusual for anybody to run. Therefore, of all the Mopar 4-speeders that you are ever likely to meet, not even one of them can compare to your first gear. Well, maybe one.
As for second with the AX15, 2.33x3.23= 7.52,
and with the Mopar is 1.92 x 3.55 =6.82 what most guys will run so you are 10% greater , so your engine can be 10% less powerful, and you guys might run neck and neck.

By third gear, your AX15, 1.44gear is about the same as the Mopar 1.40 but the 340 car is running 3.55s to your 3.23s , so, sooner or later, the 340 car is gonna leave you behind.

So that's how that works.
Finally, the combination of overdrive and 3.23s makes for a very low cruise ratio of 2.55, and 65=2060, which is about as low as you can go with a 318, and still feed it optimal ignition timing, with the factory systems. Any slower rpm, and yur gonna need a computer, to better your fuel-economy. So that means, a little more rpm will not affect your economy much. in fact, 2400 is about when it begins to drop off, which is why I run 2240. To run 2240 with the AX15 would require a rear gear of 3.55s, so, IMO, you wouldn't run any more than that, cuz of what happens in First gear If you already have these installed, I would leave them in there with the AX15. But if you have anything bigger, I would swap them out for not more than 3.23s unless you already had nothing but the 3.55s under the bench.

Wow, this is a lot of great information! Thanks for taking the time to write all that up, I learned a lot. I need to figure out what gears I have in the rear end, and go from there. After reading this I would consider keeping the ax15, but reverse gear pops out, I would have to fix the clutch geometry since the ax15 is a hydraulic clutch but the pedals are set up for a manual clutch, but the main thing is that I think I’d blow it up when the 340 goes in the car because of the power it’ll make

 

[AJ/FormS]

because of the power it’ll make

It's not the power that will break it unless you drop the clutch at 5000, lol.
It'll be the torque, which is something that factory 340s never really had a lot of.
plus on the street, with street tires, first gear is not likely to break, Second maybe, but you'll have to be mean to it

My 367 kept tearing up the clutches, so what I did was,
1) my Diaphragm clutch had flyweights , that fly out with rop, which increases the clamping force. so
2) I reduced the static clamping so that it slipped at low rpm, just a little. No more clutch failures.
3) I did this by installing shims under each of the six retaining bolts , adjusting the thickness until I got what I wanted.
4) Now, I can almost dump the clutch and drive away, with a 10.97 starter gear. If I give it a little blip first, away it goes.


As for your hydraulic clutch, You only need about .100 TOTAL throw-out bearing travel, which includes about .080 for departure, and .020 for bearing retraction off the fingers.
Idk how much that would be at the fork.
If you don't have enough, and master is parking properly at the beginning of it's stroke, the question then is, is the master using ALL of it's available stroke.
If no, then why not.
If yes, then MAYBE, you'll need a longer-travel master. This will depend on if the slave has enough travel.

Before you buy anything, Make sure your Master is retracting all the way. This is to ensure the thing compensates for slave travel, as the clutch disc loses thickness ,due to wear.
If it doesn't compensate, the pedal will fall over time, and the slave will lose travel.

 

[AJ/FormS]

but reverse gear pops out,

If it takes a lot of effort to keep it in then it needs to come apart.
Boy. it's not often that reverse pops out.
If you can keep it in with low effort, maybe it just needs the detent looked at, or the linkage adjusted.

 

[AJ/FormS]

I need to figure out what gears I have in the rear end, and go from there

The best way to do this is to figure out if you have a limited slip or not.
If you do, then
1) jack the back of the car up to get both wheels off the ground, and
2) install some safety jacks.
3) Rotate the wheels to put the valve-stem straight up, then put a strip of masking tape to align with it.
4) similarly mark the rear yoke and index it to the rear end housing.
5) rotate the wheel exactly one turn, while simultaneously watching the driveshaft, and counting it's turns. 3.55 turns of the driveshaft to 1 turn of the wheel, would be 3.55 axle ratio ..... and so on.

If you do not have a suregrip,
a) put one wheel back on the ground, and block the car from moving.
b) this time count two wheel revolutions. Again, 4.1 turns of the driveshaft would be 4.10 axle ratio.

 

[AJ/FormS]

If you need a Mopar 4-speed, I have several to chose from, but I'm not selling them cheap. Well they might be cheaper because of the exchange rate. But IDK about tariffs.

 

[Iron and Resin]

If you need a Mopar 4-speed, I have several to chose from, but I'm not selling them cheap. Well they might be cheaper because of the exchange rate. But IDK about tariffs

It's not the power that will break it unless you drop the clutch at 5000, lol.
It'll be the torque, which is something that factory 340s never really had a lot of.
plus on the street, with street tires, first gear is not likely to break, Second maybe, but you'll have to be mean to it

My 367 kept tearing up the clutches, so what I did was,
1) my Diaphragm clutch had flyweights , that fly out with rop, which increases the clamping force. so
2) I reduced the static clamping so that it slipped at low rpm, just a little. No more clutch failures.
3) I did this by installing shims under each of the six retaining bolts , adjusting the thickness until I got what I wanted.
4) Now, I can almost dump the clutch and drive away, with a 10.97 starter gear. If I give it a little blip first, away it goes.


As for your hydraulic clutch, You only need about .100 TOTAL throw-out bearing travel, which includes about .080 for departure, and .020 for bearing retraction off the fingers.
Idk how much that would be at the fork.
If you don't have enough, and master is parking properly at the beginning of it's stroke, the question then is, is the master using ALL of it's available stroke.
If no, then why not.
If yes, then MAYBE, you'll need a longer-travel master. This will depend on if the slave has enough travel.

Before you buy anything, Make sure your Master is retracting all the way. This is to ensure the thing compensates for slave travel, as the clutch disc loses thickness ,due to wear.
If it doesn't compensate, the pedal will fall over time, and the slave will lose travel.

Wow, you are a wealth of knowledge. All of this sounds so far beyond me, I have zero experience with anything related to transmissions. I was honestly going to pay a shop to figure it out, but found a deal on a 340 engine and rebuild A833 so I bought both. I checked the gear ratio the way you described and came up with 3.55 for the rear gear.

As for the reverse gear, it takes moderate to firm pressure on the shifter to hold it in gear when I back up. Not too worried about it, since I think it’ll be coming out anyways; I plan on building the 340 to have a good bit more hp and tq than factory.

Do you have any general advice or thoughts on a manual clutch vs hydraulic? I’ll most likely just go with manual for the a833 since that’s what it came with from the factory and my pedals are already set up for it, but if you have any thoughts I’d love to hear. Thank you

 

[AJ/FormS]

Oh well if you already have the A833, And 3.55s, that's a no brainer, just stuff that A833 in there, with a regular clutch.
As for the 340,
keep in mind that Adding power takes rpm, which almost always takes torque off the bottom. Depending on what you do for a cam and cylinder pressure, you can loose as much rpm off the bottom as you gain on top.
In a street car, this is usually not a good thing, which is why I started with a 360.
If yur not careful, you'll be into 3.91>4.30s in a hurry; and then you'll probably want an overdrive.


If you go to far, then you'll probably end up with an automatic.,,,, for several reasons;
1) with a manual trans, as the idle-rpm goes up, you can't drive slow anymore. 800 rpm with a 2.66 low and 3.55s is about 6.8mph. So parading is out, and you might have to slip the clutch out like a Mustang, because of the lack of Idle/low-rpm torque.
whereas with an automatic; you get
2) more torque multiplication in the convertor, that
3) allows you to run a lil less rear gear, to
4) reduce your hiway rpm.
5) pretty much ideal, would be a 4-speed automatic with a Lock-up converter is The Mopar overdrive has a ratio of .69, which means that you can run say 4.30s and get yur bottom-end back, yet she will cruise like 2.97s, for 65=2400; perfect for a modest cam.
With 4.30s in the back, the engine shouldn't be particularly fussy about the stall, in a streeter.
Yes you could run that with 3.55s for 65= 1980, but the engine will NOT get you any efficiency down there. it might actually lose mpgs; actually I'm sure it would.
Plus, the starter gear will be 3.55 x 2.45= a paltry 8.70, so even if the TC has an internal hydraulic equivalency ratio of 1.8 to 1, making your 8.70Starter feel like about 15.66 for a second; that will be brief.
I mean you could try it since they're already installed.

Personally
I'm not liking an HO 340, 3.55s, and a manual trans.
If I was stuck with a 340,
I'd get me a 4-speedLU auto, some alloy heads, run a modest fast-rate tight LSA cam, at high pressure. Now it's set up about right for a streeter, cruising at 65=2400; with 4.30s and overdrive. Badaboom.

If I had to use a Mopar-manual trans, I'd put a GVod on the back of a Commando, run a 3.73 gear, and use the GV as a splitter. Again, 65=2350
The ratios would be 3.09-2.41-1.92-1.5/1.4-1.09/1.00-.78
The first 4 will get you to 86mph @6000, 1.4 will get you 92 mph@6000
1.09 ratio will get you 6000= 118
about 95% of the time you would be shifting
3.09-1.92-1.4-1.09-.78, splits of .62-.73-.78-.72od......... Badaboom.
That's what I already did but with an HO360, 3.55s, and trapping about 5700.
Parting shot.
With a 340, a Mopar 2.66 box, and 3.55s,
I would go easy on the cam,
and rather pump it up to say 195psi with alloy heads.
Some guys will tell you that alloy heads do not require special considerations. To that I say, try running 195psi with iron heads, on the street with pumpgas, day-in/day-out. It's never gunna survive.
BTW, my 367 ran that on 87E10. yes at full timing.
This is NOT a brag, just a testimony.

 

[RustyRatRod]

Wow, this is a lot of great information!

That's one opinion.

 

[RustyRatRod]

Wow, you are a wealth of knowledge.

That's another opinion.

 

[Iron and Resin]

Oh well if you already have the A833, And 3.55s, that's a no brainer, just stuff that A833 in there, with a regular clutch.
As for the 340,
keep in mind that Adding power takes rpm, which almost always takes torque off the bottom. Depending on what you do for a cam and cylinder pressure, you can loose as much rpm off the bottom as you gain on top.
In a street car, this is usually not a good thing, which is why I started with a 360.
If yur not careful, you'll be into 3.91>4.30s in a hurry; and then you'll probably want an overdrive.


If you go to far, then you'll probably end up with an automatic.,,,, for several reasons;
1) with a manual trans, as the idle-rpm goes up, you can't drive slow anymore. 800 rpm with a 2.66 low and 3.55s is about 6.8mph. So parading is out, and you might have to slip the clutch out like a Mustang, because of the lack of Idle/low-rpm torque.
whereas with an automatic; you get
2) more torque multiplication in the convertor, that
3) allows you to run a lil less rear gear, to
4) reduce your hiway rpm.
5) pretty much ideal, would be a 4-speed automatic with a Lock-up converter is The Mopar overdrive has a ratio of .69, which means that you can run say 4.30s and get yur bottom-end back, yet she will cruise like 2.97s, for 65=2400; perfect for a modest cam.
With 4.30s in the back, the engine shouldn't be particularly fussy about the stall, in a streeter.
Yes you could run that with 3.55s for 65= 1980, but the engine will NOT get you any efficiency down there. it might actually lose mpgs; actually I'm sure it would.
Plus, the starter gear will be 3.55 x 2.45= a paltry 8.70, so even if the TC has an internal hydraulic equivalency ratio of 1.8 to 1, making your 8.70Starter feel like about 15.66 for a second; that will be brief.
I mean you could try it since they're already installed.

Personally
I'm not liking an HO 340, 3.55s, and a manual trans.
If I was stuck with a 340,
I'd get me a 4-speedLU auto, some alloy heads, run a modest fast-rate tight LSA cam, at high pressure. Now it's set up about right for a streeter, cruising at 65=2400; with 4.30s and overdrive. Badaboom.

If I had to use a Mopar-manual trans, I'd put a GVod on the back of a Commando, run a 3.73 gear, and use the GV as a splitter. Again, 65=2350
The ratios would be 3.09-2.41-1.92-1.5/1.4-1.09/1.00-.78
The first 4 will get you to 86mph @6000, 1.4 will get you 92 mph@6000
1.09 ratio will get you 6000= 118
about 95% of the time you would be shifting
3.09-1.92-1.4-1.09-.78, splits of .62-.73-.78-.72od......... Badaboom.
That's what I already did but with an HO360, 3.55s, and trapping about 5700.
Parting shot.
With a 340, a Mopar 2.66 box, and 3.55s,
I would go easy on the cam,
and rather pump it up to say 195psi with alloy heads.
Some guys will tell you that alloy heads do not require special considerations. To that I say, try running 195psi with iron heads, on the street with pumpgas, day-in/day-out. It's never gunna survive.
BTW, my 367 ran that on 87E10. yes at full timing.
This is NOT a brag, just a testimony.

A lot to consider for my upcoming build! I didn’t know that about automatic transmissions but it makes sense. I dont think parades are my thing, but I will be doing occasional short drives at highways speeds. What I’m looking to get out of this build is brutal acceleration up to about 80mph. I really only drive this car around town on joyrides and errands, and some back road cruising. With my A833 and a moderately built 340 I was thinking of re gearing to 4.30s. For the engine, I am thinking of porting/blown blend on the J heads I have, maybe higher compression pistons, air gap intake, and headers. For the cam, any recommendations on anything that will still have the lopey idle that I admittedly love but will not be impossible to drive around town and kill my low end? I’m totally ok with sacrificing drive ability for power/sound since this car is how I get my fix since I sold my 500 whp corvette that had a huge cam.

 

[AJ/FormS]

Well if 80 mph is your cut-off point, and with 4.30s, you have a three-gear car, for 80=6000.
And since racing is Not on the agenda, but the small-valve J-heads are gonna get some attention, you can build for peak-power at or near 5300 to say 5500, at most, 5700. That's gonna be about a 230degree cam. With a proper tune, that's not gonna rumble much. That is what I have in my 367. To hear it, I gotta retard the Idle-Timing and idle it down. With a shorter stroke 340, maybe you'll hear it.

Here's the thing; if yur shutting down at 80, then yur not bucking much wind, and so, you don't need Quarter-mile reserve-power. Which means that you can run a smaller cam, and less gear. Which means a reduced Cruise rpm.
AND
with 4.30s; 30mph is ; 4300 in First/3100 in Second/2250 in third ...... so, if you are plunking along at 2250, and you get the urge to floor it, The 3-1 shift is very awkward, and when you get into it, yur only gunna be in it for a second, and then into Second gear you will go.
But if yur burbling along at 3100 in Second, with dual 3" exhaust pipes, yur gonna be pissing almost everybody off.
BUIUUUUT if you go to Second, this is only 3100, and the 340 is NOT known for making torque down there. So, yur gonna have to wait until about 4000 with that 230* cam, which is 39mph. Course, if the tires light up, that's a different story.
AND
since you are already moving, Torque-multiplication off the line is not that important. Therefore, IMO, for maximum smiles, you want a gear at 30>35 mph that is at or just below the torque peak. Suppose you picked a smaller cam that torque-peaked at 3800. and you geared that to 30 mph. Now yur riding a rocket. This would be a roadgear of 10.17. Your choices for rear gears are 3.82 for first gear, or 5.30s for Second. So obviously, for a streeter, yur NOT gunna pick 5.30s.. So now, since there are no 3.82s for Mopars, your sub choices are 3.91 or 3.73. For a 340, I would probably go with 3.91s; for 30 =3900 .. Now when you stomp it on the 2-1 downshift, at 30 mph, you are definitely smiling. and first gear could go to 44mph@5800, then into Third at 4200, so again, the car is poised for performance, and 3.91s will get you 80=5450, just after peak power.
The only down sides to 3.91s are
1) a starter gear of "only" 10.40, which means that to get moving, will require a wee bit of forethought, with either more rpm to get moving , or don't try so hard to be a Mustang.
2) 65mph = 3170 rpm., still better than 3470 with 4.30s

So, in this scenario, yur looking for a cam around 224@050. and put the power in the heads. so you don't need as much rpm. Which, if you don't put bigger valves in the 360 heads, is gunna be a bit of a stretch. Well unless your Js are off a 340, lol.

As a streeter, over 90% or more of the time, your engine is gonna be at under 4000rpm. Those short bursts to 5500 or so, hardly make a ripple in the average rpm that she will be seeing. Therefore, to my way of thinking, having the combo geared right is way more important than whatever absolute power she makes. Most of the life of a streeter is spent below 50mph, so Ima thinking, getting to 50 in a blaze of glory trumps getting from 50 to 80. I mean, that's my thinking. and since I have tried about every gearbox and rear gear available to Mopars, over 55 years, I have never been happier than when I put Second gear where it needs to be, and forget about everything else. It doesn't even have to be perfect, as long as it's close. Now, I haven't had a running 340 since 1984, so I've been a 360 kindof guy ever since. This gives my combo 20 cubes of low-end grunt , and allows me to drop another cam size, which then gives the 360, an extra portion of cylinder pressure thru-out it's rev range, which is a real pleasure to drive.
When I initially installed a 230 cam, where a 223 had been, I rightaway noticed the loss of bottom end torque, and I spent several weeks bitching and moaning about it. The only cure was a lower first gear, so I got me a Commando box with a 3.09 low, for 16% more torque multiplication, in first gear. That allowed me to reclock my cam back in to straight up, which stretched my top end back out . The following winter, I pumped the Compression ratio up a little during a routine freshening. So now, I have, IMO, the most perfect Mopar combo that I could ever wish for, altho it sucks quite a bit more gas than the previous iteration.. The point is this; for me, having torque from idle to 50 mph, trumps top-end power all day long.
Btw, just so you know, this 367 has gone 93 in the Eighth, so, the top-end is not exactly a slouch, lol.

For you, maybe torque is Not your priority. IDK. So then, you will have to think hard about the big picture, so that you build your combo the right way the first time ..... I'm on my Third cam now, and have run 4 different transmission ratios and just about every rear gear available, looking for the perfect Second Road-gear, for the most part. It's pretty good now

Ask me if I miss the rumble of the 292 cam...... lol.
well sur I do,
But I'm never again going to compromise my build to get a lumpy idle.
My favorite cam ever in this 367 was the 223/230/110 cam. I could hardly hear that cam, even down to 500 rpm. But man-o-man that lil sucker pulled hard at 195psi. and the bonus was, it got great fuel-economy.

Think of it this way; if your engine makes a maximum torque of one ftlb per cube, your 340 is gonna make that somewhere north of maybe 3600. Having the right second gear ratio at say 30 mph could mean the difference of rear-wheel torque of say
340 x 1.92 x 4.30= 2807 versus
340 x 2.66 x 3.10= 2807.. or
340 x 3.09 x 2.67= 2807or
340 x 1.67 x 4.94= 2807
all the same 2807, just different gears. any one of those gear combinations, will do the same job...... in Second gear.
If I had to guess, I'd guess that your 340 will really really like the 4.30s in Second gear, but it might be overkill.
And finally;
Brutal acceleration requires the tires not to spin. Yeah good luck with that and 4.30s

 

[Newbomb Turk]

It’s about impossible to get too much first gear unless you have really low (high numerically) rear axle gears.

Since you don’t know what they are, you probably don’t.

You can fix the clutch linkage. You just need to know if you need to speed up clutch engagement or slow it down. Once you figure that out you can fix the linkage.

Here is the FACT. Torque NEVER broke a transmission. Ever. Do not buy a clutch based on its “torque” holding capability. That’s bullshit. And you’ll break parts so fast you’ll swap in an automatic.

So get torque out of your head.

What breaks these gear boxes are JUNK CLUTCHES. Thats always what breaks parts. Anyone who tells you your torque broke your transmission will show you they are talking out of their ***.

I can take a 200 hp engine (with it’s torque curve to get that) and break an 833 so fast your head will spin.

A big honking clutch with tires that bite and the next thing you know, you’ll **** third gear. It wasn’t torque that did it, it was a JUNK CLUTCH and traction that did it.

If that transmission is already in the car, you are better off saving your money and fixing the clutch linkage issue. If you are worried about breaking it, get a good clutch. You do NOT a need or even want a dual friction, ceramic double dog trick clutch.

In fact, now that I think about it, you probably have less of an issue with the clutch linkage and more of an issue with the pressure plate.

So I guess the question should be what clutch do you have now? Do you plan on slicks, cheater slicks or a drag radial tire?

Don’t get bogged down with a bunch of math until you grasp the concept of what breaks transmissions.

I don’t know what the gear splits are for that gearbox. I guess I can look them up and see how bad they really are.

For now, I’d seriously consider leaving what you have in there and fixing the other issues.

Unless you are drag racing I think you are going backward with the 833.

I went back though all the jabberwocky and you have 3.55’s. That’s not a low rear axle ratio. I consider that pretty tall.

You got **** bombed with a bunch of math that doesn’t matter. Let’s do the simple math because no matter what, you are stuck with the ratios the transmissions come with.

If you have a 3.55 rear axle ratio and you want to find out the overall ratio of any gear in the gear box, it’s simple multiplication. So I’ll run through the common first gear ratios.

3.55*2.47=8.769 first gear.
3.55*2.66=9.443 first gear
3.55*3.09=10.97 first gear

Those are your options for 833 first gear ratios.

I’ve driven them all and I can say that the 8.769 is absolutely miserable to drive. Just garbage.

The 9.443 is SLIGHTLY better but you have to manipulate to the clutch and dick around. It’s not fun.

The 10.97 is TOLERABLE. That is the absolute tallest first gear I would use if you have an 833 box. The other two options are miserable to drive.

If you had a lower rear axle ratio then it would get better. Let’s do the simple math of what you can control.

4.10*2.47=10.127
4.10*2.66=10.906
4.10*3.09=12.669

The issue with that is now your 1:1 (fourth gear) is 4.10 instead of 3.55 and you have more rpm at any cruise MPH. Some guys hate that.

So you need to understand this basic relationship be for you do any other math because it’s essentially irrelevant as you have no control over what the other gear ratios in the transmission are.

I need to look up the ratios for the 5 speed you have.

 

[Newbomb Turk]

Ok, here are the ratios for the gearbox you have.

3.83
2.33
1.44
1.00
.079

My quick math says that would give you this: 3.83*3.55=13.597

IMO thats a decent first gear for a 3300 plus pound car with your rear axle ratio. The overdriven fifth gear means you can run with traffic and not run the engine over its peak torque.

You are stick with the splits. Just like you will be with any transmission.

As a FWIW so you know I’m not talking out of my *** my first gear is 15.0792 and if I could get more first gear I would. And like you, I live with the splits the gear box has. It is what it is.

As another FWIW with the 13.597 first gear you can easily use an aluminum flywheel. The car will drive better with it. You will notice from stop light to stop light and in the gear changes how much more responsive the engine is to throttle input.

You have to learn to drive a bit differently but it’s much nicer to drive.

I’d seriously reconsider swapping in an 833. And one more FWIW, a 318 and a 340 have the same stroke. Don’t dwell on torque. It will drive you mad as a hatter.

 

[Iron and Resin]

Thank you for taking the time to write all that up for me!! I think you’ve convinced me to keep my current transmission until it either gets too worn out, breaks, or I get bored and just want a change. Math is certainly not my strong suit so I appreciate you breaking it down simply, it sounds like I would be happier if I geared down to 4:10 or 4:30? I like the sound of the 4:30s.

As for my clutch, it engages too slow. If I try to shift fast, I have to wait for the clutch pedal to slowwwly make its way back all the way out and the clutch to be engaged. Would this mean I need to go shorter with the linkage? I don’t understand how the pedals being designed for a mechanical clutch ruins the driveability of my current hydraulic clutch setup.

Do you think an aluminum flywheel would be a good fit for my 340? I loved the fast revving / instant throttle response of the corvette I had and I miss that.

Thank you again for your help