Converting an automatic 74 Swinger to a 4 speed

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George Lawicki

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Hey guys,

just curious, Is it possible to convert an auto to a 4speed?? Say I had a 360 motor, 727 Trans?? Would parts be available? How difficult would it be? How costly? Would it be cool and not look stupid?
 
I have done it several times. I might be able to scare up one more nearly complete swap-over.
There can be hurdles but none are insurmountable. The biggest deal is putting the floor hump in, in the right place. ( I don't have one of those.)

But the real question is why?
With modern convertor technology and a rightly built engine, the automatic, gear for gear, will have the advantage in every aspect except perhaps point to point, hiway fuel-economy. And you can overcome that with a loc-up.
If a streeter
Don't say so you can row gears, cuz with 3.23s (even 3.55s and 3.73s), there is only one gear change at WOT from zero to 60mph; and at part throttle, just two, and the built auto downshifts faster in both cases, usually faster upshifts, and sometimes/often comes up with more torque.
But if you just want a 4-gear, there can no argument be made against wanting something,lol.
 
It can be done. For the price it takes for it all, you might consider a TKO swap. Moist of them are designed for auto to TKO swap.
 
Would it look stupid? That depends on you. If you do the job with duct tape, bailing wire and sheet metal screws, yeah, that'd look purdy stupid. As has been mentioned, it's not a bolt in deal. It requires good mechanical skill and some body work, since a big portion of the transmission tunnel has to be replaced. It's a big job, but absolutely doable.
 
basically, I was just trying to capture that 60's vibe with the 4 speed. You know slamming gears etc lol Its just a thought as of now
 
$$$ lots of jack!! I've wanted to do several of mine but the funds always stop me...
 
Hey guys,

just curious, Is it possible to convert an auto to a 4speed?? Say I had a 360 motor, 727 Trans?? Would parts be available? How difficult would it be? How costly? Would it be cool and not look stupid?

Not for the faint of heart. I'm speaking from experience.

You'll need...
A-833 transmission (and possibly a rebuild kit)
Hurst shifter body (and possibly a rebuild kit)
Shifter to trans adapter plate, plus bolts
Shifter handle
Shifter handle knob
Shifter handle rubber boot
Floor to shifter handle boot bezel ring
Shift linkage rods, and accessories
Bell housing, complete with inspection over
Bell housing ball stud
Clutch fork
Clutch fork return spring
Clutch fork boot
Clutch fork pivot inside bell housing
Clutch fork adjustment rod
Throw out bearing
Pressure plate
Clutch disc
Flywheel
Pilot bearing
Clutch pedal assembly
Clutch rod
Z bar
Z bar bushings
Frame ball stud
Frame ball stud support bracket
Firewall clutch rod boot
Clutch and brake pedal rubber covers
Clutch and brake pedal bezels (optional)
Reverse lamp switch
Reverse lamp wiring harness
Reverse gear indicator light (optional)
Speedometer cable and gear (IDK if the 727 cable can swap over)
4 speed trans tunnel hump
4 speed carpet
Driveshaft
U joints
Floor shift steering column (if currently a column shift)
New starter (possibly)
All associated bolts, bushings, bearings, seals, gaskets, and retainers

I sure I've missed something, but this list will get you started.
If you have the cash, call Brewers and they will set you up with everything you need.
 
I did it to my 69 Barracuda Fastback. It was a lot of work, but it was quite satisfying. Don't try it unless you are a pretty good wrench turner. With the exception of welding in a 4 speed hump, it is pretty straight forward. @AJ/FormS makes a good point. You can get exceptional performance with an automatic. But I did mine for the same reason you mentioned, to bang through the gears like I did 50 years ago. I was very lucky when I converted mine about 15 years ago. I found a 69 Barracuda Fastback 340 4 speed car with console advertised on Ebay as in fairly good shape but needing a complete restoration. I bought it sight unseen for $2700. I figure I had another $500 wrapped up in driving up to the Chicago are, renting a trailer and towing it back to Kansas. What I wound up with was a car that had quite a bit of rust, but it had a running 340 with cast iron manifolds, ALL the 4 speed stuff I would need, 8.75 Sure grip with 3.55 gears, decent interior, Decent sbp ralleye wheels, and a lot of other good pieces. I pulled all the four speed stuff, sent the shifter and pedal assembly to Brewers (what a great bunch of people) to be restored, had the top of the console re-chromed and bought a new flywheel. Then I sold the running 340, the automatic from my car and the 8.75 rear end out of the parts car $2400, and then parted the rest of the car out on Ebay. I did it all with regular 10 day auctions, no buy it now. I was amazed at what some of the stuff sold for. I wound up with a 4 speed conversion that was better than free; I actually put money in my pocket.
 
In a streeter,
to properly bang gears, you sorta need ~4.30s, and a short period cam, then shift at 5000 or so. With 26.7" tires your redline roadspeeds are; 35,48,66, and 92; there you go; 3rd bangshift comes at or near the speed limit. I can tell you that even a smoggerteen feels like a racecar with 4.30s.. But, of course, cruising 65 mph will not be fun as the rpm is ~3500. 55 is doable at 2970; but 55 feels sooooo slow. On the flipside, 500rpm with that short-period cam is 3.5mph with the 2.66low, and 3mph with a 3.09. To make it interesting, put a small-port top-end on that 360, with a TQ, and let her mooooooooooan. Gosh that is soooooo addictive. You will be having sooooo much fun.
I would consider a 3-pedal solid longroof A or F roller, as partial-trade, with a black,brown,or tan interior, lol.
Too bad yur so far away.

BTW;
@jonn6464 mentions that you need a driveshaft. What you really need is the 727 front yoke, cuz the standard 2.66 trans comes with the larger than 904 mainshaft. However, the 6-cyl F-body overdrive trans comes with the 904-sized yoke. With this trans, you can run 3.73s or even 3.55s
Here is a roadgear comparo; first the 2.66/4.30s, then the overdrive with 3.73s, then with 3.55s; With their associated 65mph cruise rpms, and 5000rpm roadspeeds.
11.44-8.26-6.02-4.30;65=3513 shifts 35/48/66/92 Saweet!
11.53-6.23-3.73-2.72 ;65=2222 shifts 34/64/107/146;1st&2nd not bad
10.97-5.93-3.55-2.59 ;65=2116 shifts 36/67/112/154;It's going away
as you can see, the overdrive box trades away the 48mph gearchange to get that low cruise rpm. You cannot get it back without sacrificing first gear; so you need a stout engine to pull that 5.93/6.23 second gear at low rpm; like a Magnum, that is to say, a Hi-compression engine. The bonus here is that with the Hi-C /short-period cam/ teener, and cruising at 2100/2200, she has the potential to be very fuel stingy on the hiway.
But in all honesty, a Five-speed would be a better choice.
Something with ratios like the AX-15, or NV3500; the former has ratios of
3.83-2.33-1.44-1.00-.79; splits of (.61-.62-.69-.79) and the latter has
3.49-2.14-1.38-1.00-.73; splits of (.61-.644-.725-.73).. I like the NV for its better placed Second and higher First thus having more progressive shifts;
The NV ratios work fairly well with 3.73s with roadgears of
13.02-7.98-5.15-3.73-2.72, and 5000rpm shifts at
31/50/77/107/ and forget winding up od,lol. A great second gear for a 318 is around 8.00. Compare Second gear of 7.98 here versus 8.26 with the 4.30/A833 combo; and 65=2225 with those 3.73s.. But the NV does require some serious tunnel work. See pic below, it's too tall to fit into the factory tunnel.
You can make
a similar combo with a Commando A833 and a GVod but it gets pricey. The advantage here is no tunnel work, a true bolt-in, except 2 things; the driveshaft needs to be shortened, and you have to make yur own shifter mount.. The ratios would be;
3.09-1.92-1.40-1.00-.78od and roadgears with 4.10s are
12.67-7.87-5.74-4.10-3.20.. With 5000rpm shifts the road-speeds are;
31/51/69/97/ and forget od again. and 65=2740 . I have run this combo for about a year with a smoggerteen, and I liked it. (edit;actually I ran 4.30s) With an HO367, I swapped the 4.30s for 3.91s then 3.55s, and liked the 3.55s. That is what is in my car today, many years later; (Commando/GVod/3.55s) and she loves it.The road ratios with this combo are;
10.97-6.82-4.97-3.55-2.77, The 5000 rpm shiftspeeds are;
36/58/80/112 and 65=2240
But you lose the shift into Third at or below the 65 mph speed-limit, it moves to 80mph. No big deal for the HO367..... but again, you sorta lose the shift banging thing; not going into third until 80 at WOT
To it's credit, city driving and short shifting with this combo is a lotta fun, and the combo always has a fun gear to play with. In everyday driving I shift at about 2800. The 367 is pulling easy and sounds great thru the full-length 3" duals, this puts the shifts at 20/33/45/63 and into od at 65.
But with the GVod I usually shift into 3od first, then 4od. The road-speeds, shifting at 2800 this way are;
20/33/45/57/65 , and the splits are a nice progressive
62-.73-.78-.72 into final-drive


upload_2021-4-25_6-31-2.jpeg
 
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I bought a TKO 600 kit from Silver Sport transmissions, $6081.00 Complete kit, still had to buy a 4 speed cover for the console repop $ 400.00. Oem mopar dust boot around shifter handle $40.00
Cut out tunnel, make new tunnel, make brace to connect frames back together, modify the console to fit bigger tunnel. It's time and money. Oh forgot you have to add the pedals, that was fun. if you have a trans speed sensor and you want to used factory speedo you need a electronic cable drive unit, on and on if you do a TKO kit.
The old 4 speeds would be a walk in the park to convert to. My $.02 worth.
 
In a streeter,
to properly bang gears, you sorta need ~4.30s, and a short period cam, then shift at 5000 or so. With 26.7" tires your redline roadspeeds are; 35,48,66, and 92; there you go; 3rd bangshift comes at or near the speed limit. I can tell you that even a smoggerteen feels like a racecar with 4.30s.. But, of course, cruising 65 mph will not be fun as the rpm is ~3500. 55 is doable at 2970; but 55 feels sooooo slow. On the flipside, 500rpm with that short-period cam is 3.5mph with the 2.66low, and 3mph with a 3.09. To make it interesting, put a small-port top-end on that 360, with a TQ, and let her mooooooooooan. Gosh that is soooooo addictive. You will be having sooooo much fun.
I would consider a 3-pedal solid longroof A or F roller, as partial-trade, with a black,brown,or tan interior, lol.
Too bad yur so far away.

BTW;
@jonn6464 mentions that you need a driveshaft. What you really need is the 727 front yoke, cuz the standard 2.66 trans comes with the larger than 904 mainshaft. However, the 6-cyl F-body overdrive trans comes with the 904-sized yoke. With this trans, you can run 3.73s or even 3.55s
Here is a roadgear comparo; first the 2.66/4.30s, then the overdrive with 3.73s, then with 3.55s; With their associated 65mph cruise rpms, and 5000rpm roadspeeds.
11.44-8.26-6.02-4.30;65=3513 shifts 35/48/66/92 Saweet!
11.53-6.23-3.73-2.72 ;65=2222 shifts 34/64/107/146;1st&2nd not bad
10.97-5.93-3.55-2.59 ;65=2116 shifts 36/67/112/154;It's going away
as you can see, the overdrive box trades away the 48mph gearchange to get that low cruise rpm. You cannot get it back without sacrificing first gear; so you need a stout engine to pull that 5.93/6.23 second gear at low rpm; like a Magnum, that is to say, a Hi-compression engine. The bonus here is that with the Hi-C /short-period cam/ teener, and cruising at 2100/2200, she has the potential to be very fuel stingy on the hiway.
But in all honesty, a Five-speed would be a better choice.
Something with ratios like the AX-15, or NV3500; the former has ratios of
3.83-2.33-1.44-1.00-.79; splits of (.61-.62-.69-.79) and the latter has
3.49-2.14-1.38-1.00-.73; splits of (.61-.644-.725-.73).. I like the NV for its better placed Second and higher First thus having more progressive shifts;
The NV ratios work fairly well with 3.73s with roadgears of
13.02-7.98-5.15-3.73-2.72, and 5000rpm shifts at
31/50/77/107/ and forget winding up od,lol. A great second gear for a 318 is around 8.00. Compare Second gear of 7.98 here versus 8.26 with the 4.30/A833 combo; and 65=2225 with those 3.73s.. But the NV does require some serious tunnel work. See pic below, it's too tall to fit into the factory tunnel.
You can make
a similar combo with a Commando A833 and a GVod but it gets pricey. The advantage here is no tunnel work, a true bolt-in, except 2 things; the driveshaft needs to be shortened, and you have to make yur own shifter mount.. The ratios would be;
3.09-1.92-1.40-1.00-.78od and roadgears with 4.10s are
12.67-7.87-5.74-4.10-3.20.. With 5000rpm shifts the road-speeds are;
31/51/69/97/ and forget od again. and 65=2740 . I have run this combo for about a year with a smoggerteen, and I liked it. (edit;actually I ran 4.30s) With an HO367, I swapped the 4.30s for 3.91s then 3.55s, and liked the 3.55s. That is what is in my car today, many years later; (Commando/GVod/3.55s) and she loves it.The road ratios with this combo are;
10.97-6.82-4.97-3.55-2.77, The 5000 rpm shiftspeeds are;
36/58/80/112 and 65=2240
But you lose the shift into Third at or below the 65 mph speed-limit, it moves to 80mph. No big deal for the HO367..... but again, you sorta lose the shift banging thing; not going into third until 80 at WOT
To it's credit, city driving and short shifting with this combo is a lotta fun, and the combo always has a fun gear to play with. In everyday driving I shift at about 2800. The 367 is pulling easy and sounds great thru the full-length 3" duals, this puts the shifts at 20/33/45/63 and into od at 65.
But with the GVod I usually shift into 3od first, then 4od. The road-speeds, shifting at 2800 this way are;
20/33/45/57/65 , and the splits are a nice progressive
62-.73-.78-.72 into final-drive


View attachment 1715728260

They are still automatics. They suck *** to drive. Dumbs down the experience. I learned to drive on 3.23’s and I banged gears all the time.

Go for the stick. The automatic is symptomatic of society today. Most people under 35 can’t drive a stick. Just stupid.

And don’t get me started on the worthless CV transmissions. It’s like driving an oversized snowmobile. Just straight junk. JUNK.

OP, go for the stick. No reason not to. If I had to have an automatic in my car I’d quit driving and ride a bus or get an Uber.
 
New TKO 600 5 speed with 3:73 SG and 5.7L Hemi with 333.0 HP and 371.9 FtLb on rear wheels is fun to drive.
I get fpg now (Fun Per Gallons). That bent up over shifter sticking out of a console is awesome.
I hope the OP goes for it, he will forget about all the trials, troubles when he dumps clutch in 1st, and bangs 2nd and hold on.
 
I converted my 68 barracuda and my 70 dart. It was easy for me. I collected ALL the parts first. The actual swap, from running driving automatic to running driving 4 speed, took me 3 days. If ya have all the factory parts they kinda fall into place.
I say go for it! I hate automatics, they're pretty lame and absolutely most definitely boring.

I'm actually in the middle of converting my 2001 Ram 2500 Cummins to manual nv5600 6 speed. That's a little more difficult and certainly more expensive. To hell with that piece of **** 47RE junk of a shithole transmission.
 
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Well ok then,lol.
I will go out to my sheds later in the week, when it warms up and is not raining; and see what I can all scare up. Just in case you PM me. No pressure lol, I've had that stuff around for a few years already.
 
Well ok then,lol.
I will go out to my sheds later in the week, when it warms up and is not raining; and see what I can all scare up. Just in case you PM me. No pressure lol, I've had that stuff around for a few years already.
Iam really on the fence about it. But Iam interested in what you may have. I tried to PM you your box is full
 
Iam really on the fence about it. But Iam interested in what you may have. I tried to PM you your box is full


LOL...his box is always full. I wanted to send him a PM once but his box was full. By the time he cleared it I forgot why I PM’d him LOL. May be better off sending up smoke signals.


EDIT: I say go for it. Automatics are for guys who can barely use a pop up toaster.
 
It's possible but it isn't cheap, most annoying part is installing the pedals. I wanna say it was around $2500 to swap my '74 but I used mostly new parts clutch and shifter linkage wise. I was on the fence for about 5 years on doing it, I collected parts on and off 2 other times before I bit the bullet. I honestly have no regrets with going to a 4-speed in the car, it'll be better with a gear in the car.
 
LOL...his box is always full. I wanted to send him a PM once but his box was full. By the time he cleared it I forgot why I PM’d him LOL. May be better off sending up smoke signals.
Oh so that's what happened; I guess I'll delete the room I made for you then...... lol.
 
basically, I was just trying to capture that 60's vibe with the 4 speed. You know slamming gears etc lol Its just a thought as of now
I recall reading in the Direct Connection Racing Manual (I cut my Mopar teeth on the blue "bible") that the engineers highly recommended against the swap. Yes, it can certainly be done. The DC engineers said that it was quite involved, and getting the angles just right can mean the difference between a successful project or a failed one. Like AJ said, if that is in your heart, then go for it. Alternatively, you can convert a 727 valve body to full manual to have the thrill of shifting without the hassle of the swap. Best of both worlds. For me, a good automatic shift kit with the correct kickdown linkage adjustment makes me smile! I can stomp the gas at 30MPH and the trans will go into first gear. That without the hassle of a clutch.
 
I recall reading in the Direct Connection Racing Manual (I cut my Mopar teeth on the blue "bible") that the engineers highly recommended against the swap. Yes, it can certainly be done. The DC engineers said that it was quite involved, and getting the angles just right can mean the difference between a successful project or a failed one. Like AJ said, if that is in your heart, then go for it. Alternatively, you can convert a 727 valve body to full manual to have the thrill of shifting without the hassle of the swap. Best of both worlds. For me, a good automatic shift kit with the correct kickdown linkage adjustment makes me smile! I can stomp the gas at 30MPH and the trans will go into first gear. That without the hassle of a clutch.
OH? enlighten me on this!
 
Im currently restoring a 76 swinger that was an automatic car. Im putting in a cast iron od833 out of a 76 dart sport behind a mild 360. So everything is as it would have came in 76. I had numerous parts cars which made it easy
 
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