A999 as a street/strip trans.

-
M

motorpirate

serial mopar owner
Joined
Nov 4, 2007
Messages
719
Reaction score
556
Location
northern KY
So Dany's Magnum swap has been successful enough that it is starting to eat the original 18 spline 100K mile trans. No suprise...
So we want to build a "later" trans for it and save the '66 unit to use with the 273 in another project.
However, finding a core locally has proved harder than I would have thought.
The only thing I have found close is in a 1985 van.
From what info I have "if" its not a 727 (don't want it) then it must be a 999 with a lock up converter.
I have read every 999 thread on here I could find and don't see a clear answer to how to use an aftermarket converter with this trans, Or I am to dense to understand the answer!!

So what we would like to know is:

Can you change the input shaft/pump to accept a standard "off the shelf" converter?
If so, what year/application parts.

Has anyone had a "performance" converter built with the lockup converter splines?
Or had anyone rebuild the lockup converter as a high stall?

We are not really interested in retaining the lock up feature and are just looking to raise the stall speed a little over the stock '66 converter.

Is it possible the van converter has a higher stall speed than what we have now in spite (or because of) the lock up feature?

I only have about $600 to spend on this including the purchase of the trans itself (knocking out the drag radials we thought would be our next upgrade) so I don't think a custom converter is in the cards if we are to get back to the track this season.


If you aren't familiar with Dany;s project in the Magnum Swap and racing forums here are the details.

'66 Barracuda
5.9 Magnum with lunati 20200715 roller.
Dougs headers
8.25 with 3.55's SG and 26" tires
3200 lbs with driver.
Best of 14.42 @98.6 MPH with a terrible 60'

Thanks so much guys, we would never have made it this far without all the help from this site!!!
 
I had a 998 built up with a performance TC and stayed with the lock up. Set up to shift at 5200. The unit you may have is hydraulic only operated lock up no electronics or solenoids involved. It locks up at about 40-45mph and works good,lowering rpms and has a real 1:1 feel to it like a 4spd. I would not eliminate it on your 999 which is
a heavier duty unit than the 998. I have to add 98mph is not doing well with the combo you have.
 
66jim said:
I had a 998 built up with a performance TC and stayed with the lock up. Set up to shift at 5200. The unit you may have is hydraulic only operated lock up no electronics or solenoids involved. It locks up at about 40-45mph and works good,lowering rpms and has a real 1:1 feel to it like a 4spd. I would not eliminate it on your 999 which is
a heavier duty unit than the 998. I have to add 98mph is not doing well with the combo you have.
Click to expand...

66jim said:
I had a 998 built up with a performance TC and stayed with the lock up. Set up to shift at 5200. The unit you may have is hydraulic only operated lock up no electronics or solenoids involved. It locks up at about 40-45mph and works good,lowering rpms and has a real 1:1 feel to it like a 4spd. I would not eliminate it on your 999 which is
a heavier duty unit than the 998. I have to add 98mph is not doing well with the combo you have.
Click to expand...
Sounds like you have built what i need to build.
She has been letting the trans shift itself (4k rpm or so) but with transmissions age, and her weak tiny "girl feet" I can hear it shift A LOT earlier than that at times.
Thought a later trans with PTKD would eliminate this, and I would like to change the governor weight to get it to shift at 5K or so as you did.
And I agree it's not "doing well" the 60' sucks ( cooper street tires) and the early shifting is killing it. And her lack of experience. But she is having a ball so far!!
I optimistically think it can be in the 12's...

Where did your converter come from??
 
Changing a lock-up trans to a conventional trans/converter combo is done all the time. I just don't know enough of the details to explain it effectively. JW Transmissions here in Florida has been doing it for me for decades. But it does at least involve swapping the valve body, pump and shaft. Nice thing about many of the later lock-up transmissions is that they may have a 2.74 low gear as opposed to the regular 2.45. I don't know how to ID them externally and there are differences internally. But Mopar savvy transmission builders should know what it takes to do it. As you may know, lock-up transmissions have a 3/4" smooth machined tip on the input shaft.

Not sure how the lock-up features would hold up in racing applications, even with a purpose-built converter.
 
Locomotion said:
Changing a lock-up trans to a conventional trans/converter combo is done all the time. I just don't know enough of the details to explain it effectively. JW Transmissions here in Florida has been doing it for me for decades. But it does at least involve swapping the valve body, pump and shaft. Nice thing about many of the later lock-up transmissions is that they may have a 2.74 low gear as opposed to the regular 2.45. I don't know how to ID them externally and there are differences internally. But Mopar savvy transmission builders should know what it takes to do it. As you may know, lock-up transmissions have a 3/4" smooth machined tip on the input shaft.

Not sure how the lock-up features would hold up in racing applications, even with a purpose-built converter.
Click to expand...
Yea, I'm going to go through whatever we end up with myself. It been almost 35 years since I was inside a transmission but I can follow directions, have a few manuals and have more time than money.
 
Gee, I thought "14.4 @98 , with a terrible 60ft" being identical to my 1970 Swinger 340 back in 1971,.... was pretty good for 3.55s.
The problem is trapping in third gear with an automatic is like 4700rpm. Whereas my Swinger had a 4 speed and trapped at 6200 in third gear.
So Ima thinking your engine is boogying pretty good..... with those handicaps

BTW;In my transmission stash, I have a low-mileage 1965 273 904 core, and also have the skills to rebuild it. It still has the factory B&T rear flange on it. I've been saving for you since about 1975. Also have some newer slip yoke types.
 
Last edited:
motorpirate said:
So Dany's Magnum swap has been successful enough that it is starting to eat the original 18 spline 100K mile trans. No suprise...
So we want to build a "later" trans for it and save the '66 unit to use with the 273 in another project.
However, finding a core locally has proved harder than I would have thought.
The only thing I have found close is in a 1985 van.
From what info I have "if" its not a 727 (don't want it) then it must be a 999 with a lock up converter.
I have read every 999 thread on here I could find and don't see a clear answer to how to use an aftermarket converter with this trans, Or I am to dense to understand the answer!!

So what we would like to know is:

Can you change the input shaft/pump to accept a standard "off the shelf" converter?
If so, what year/application parts.

Has anyone had a "performance" converter built with the lockup converter splines?
Or had anyone rebuild the lockup converter as a high stall?

We are not really interested in retaining the lock up feature and are just looking to raise the stall speed a little over the stock '66 converter.

Is it possible the van converter has a higher stall speed than what we have now in spite (or because of) the lock up feature?

I only have about $600 to spend on this including the purchase of the trans itself (knocking out the drag radials we thought would be our next upgrade) so I don't think a custom converter is in the cards if we are to get back to the track this season.


If you aren't familiar with Dany;s project in the Magnum Swap and racing forums here are the details.

'66 Barracuda
5.9 Magnum with lunati 20200715 roller.
Dougs headers
8.25 with 3.55's SG and 26" tires
3200 lbs with driver.
Best of 14.42 @98.6 MPH with a terrible 60'

Thanks so much guys, we would never have made it this far without all the help from this site!!!
Click to expand...
I converted mine by finding a slant six pump and input shaft and I went with a manual shift valve body.
A 999 will probably have the low gear set and possibly the 5 clutch drum with a beveled stator and high gear drum. If you want to use the beveled 5 clutch drum in a non lockup application, you will have to have the bevel custom machined onto the non lockup slant six stator. Or your other option is to use a 4 clutch drum with thinner frictions to get 5 clutches.
The other area of concern is again with the stator. If you use the forward clutch hub from the 999 with the slant 6 stator, the sealing ring bore diameter needs to be machine bigger by .060 thou.
If machining is not available, then you could also use the slant six forward clutch with the slant six stator, but your clutch count will be less because of the snap ring location.
Do not use a non lockup forward clutch with a lockup stator or you will have a no drive situation because of the difference in sealing ring diameter(.060) mentioned. Be sure your end plays are within spec.
 
Last edited:
Duane said:
I converted mine by finding a slant six pump and input shaft and I went with a manual shift valve body.
A 999 will probably have the low gear set and possibly the 5 clutch drum with a beveled stator and high gear drum. If you want to use the beveled 5 clutch drum in a non lockup application, you will have to have the bevel custom machined onto the non lockup slant six stator. Or your other option is to use a 4 clutch drum with thinner frictions to get 5 clutches.
The other area of concern is again with the stator. If you use the forward clutch hub from the 999 with the slant 6 stator, the sealing ring bore diameter needs to be machine bigger by .060 thou.
If machining is not available, then you could also use the slant six forward clutch with the slant six stator, but your clutch count will be less because of the snap ring location.
Do not use a non lockup forward clutch with a lockup stator or you will have a no drive situation because of the difference in sealing ring diameter(.060) mentioned. Be sure your end plays are within spec.
Click to expand...
That is the 2nd time I have read the slant 6 pump/input shaft thing. Does it have to be slant 6 999? Or any non lockup 904?
I have a brother in law that is a machinist ( but not a transmission guy) and access to a large lathe and mill. Can we just copy the dimensions of the 999 pump for those 2 changes?
 
AJ/FormS said:
Gee, I thought "14.4 @98 , with a terrible 60ft" being identical to my 1970 Swinger 340 back in 1971,.... was pretty good for 3.55s.
The problem is trapping in third gear with an automatic is like 4700rpm. Whereas my Swinger had a 4 speed and trapped at 6200 in third gear.
So Ima thinking your engine is boogying pretty good..... with those handicaps

BTW;In my transmission stash, I have a low-mileage 1965 273 904 core, and also have the skills to rebuild it. It still has the factory B&T rear flange on it. I've been saving for you since about 1975. Also have some newer slip yoke types.
Click to expand...
That's her on the left..

Screenshot_20190929-114816_Gallery.jpg
 
Well at 3200pounds, gearing at the traps will be your friend.
But the Bulletin book says at 14.4/3200# your P/W is~.061 so 3200x061=195hp. So; I guess I was optimistic.
However with the handicaps of street gears, street suspension, and a 2.3 60ft, I'll guess the dyno would spit out more like 3200x.7=224hp. Just guessing.
Now starts the quest for the missing, AWOL ,ponies. Those missing ponies could put you into the thirteens,just.
But I'm guessing you didn't choose that 20200715 cam for a low ET.
264/2701/112/+6 ; .785/.485 lift,and 213/219@.050.
But rather for the boatload of torque it makes at lower rpms.
 
This has nothing to do with the transmission question but for three years my daughter raced my 64 Fairlane and she had a problem with flooring the gas pedal. So I set it up where the carb was wide open and the gass pedal was an 1/8" off the carpet, the other thing was I had her slide the seat forward about 3" from the going for a cruze position it was in. This made it much easier for her to be more consistent with full pass's.
 
motorpirate said:
That is the 2nd time I have read the slant 6 pump/input shaft thing. Does it have to be slant 6 999? Or any non lockup 904?
I have a brother in law that is a machinist ( but not a transmission guy) and access to a large lathe and mill. Can we just copy the dimensions of the 999 pump for those 2 changes?
Click to expand...
It does not even have to be a slant six, just any 3 speed non lockup.
Yes you could just duplicate it on a lathe. If you do both it is one setup in the lathe. The bevel is just for clearance. If you try to put the 5 clutch 999 drum on the slant 6 stator you will see where the interference is. Do cut any more than necessary. Just enough to get the drum to seat and not rub. The beauty of this mod is you can then use any front drum, beveled or not. The sealing ring diameter
Machining is only necessary if you want to use the 4 clutch 999 forward clutch hub. This hub is bigger in diameter in the sealing ring area and will not slide into the bore on a non lockup stator.
If you use the slant 6 clutch, no machining is required.
Also if you use the 999 forward clutch hub you will have to press out and change the input shaft to the non lockup one. If you use the slant 6 forward clutch hub and the input shaft that's already in there,the whole job is a bolt in.
Another way to identify the correct stator is the non lockup has 2 balls and the lockup has 3. You want a 2 ball stator.
 
motorpirate said:
That is the 2nd time I have read the slant 6 pump/input shaft thing. Does it have to be slant 6 999? Or any non lockup 904?
I have a brother in law that is a machinist ( but not a transmission guy) and access to a large lathe and mill. Can we just copy the dimensions of the 999 pump for those 2 changes?
Click to expand...
Watch your terminology here. The pumps are all the same, it is the stator that is different. There are two halves to the pump assembly.
The one half is the stator. The side with the rotors is the pump.
 
Duane said:
Watch your terminology here. The pumps are all the same, it is the stator that is different. There are two halves to the pump assembly.
The one half is the stator. The side with the rotors is the pump.
Click to expand...
Got it, I think.
Trust me if the 999 comes through, I'm sure I will be pestering you with pictures before we cut anything!!!
Only reason I asked if it had to be slant 6 or not is I am looking at a few "core" transmissions Wednesday that are like 4 hours away. I want to get at least one as a backup if the 999 falls through. they are V8 transmissions and I wondered if one of those would work is all.
 
AJ/FormS said:
Well at 3200pounds, gearing at the traps will be your friend.
But the Bulletin book says at 14.4/3200# your P/W is~.061 so 3200x061=195hp. So; I guess I was optimistic.
However with the handicaps of street gears, street suspension, and a 2.3 60ft, I'll guess the dyno would spit out more like 3200x.7=224hp. Just guessing.
Now starts the quest for the missing, AWOL ,ponies. Those missing ponies could put you into the thirteens,just.
But I'm guessing you didn't choose that 20200715 cam for a low ET.
264/2701/112/+6 ; .785/.485 lift,and 213/219@.050.
But rather for the boatload of torque it makes at lower rpms.
Click to expand...
This is the motor I "copied" from this very site. It has been awesome so far. Pulls like a Grand National I had in the '90's.
360 TrueStreet Magnum Build
 
motorpirate said:
Got it, I think.
Trust me if the 999 comes through, I'm sure I will be pestering you with pictures before we cut anything!!!
Only reason I asked if it had to be slant 6 or not is I am looking at a few "core" transmissions Wednesday that are like 4 hours away. I want to get at least one as a backup if the 999 falls through. they are V8 transmissions and I wondered if one of those would work is all.
Click to expand...
In my limited experience the 999 with lockup torque converter
Is the strongest versions ever made of these trans. They usually have the low gear set, 4 pinion steel planetaries, bigger roller clutch
That is riveted in, and other small improvements over earlier versions. They are plentiful in the wrecking yards, but people are afraid of them because of the lockup feature.
 
motorpirate said:
Got it, I think.
Trust me if the 999 comes through, I'm sure I will be pestering you with pictures before we cut anything!!!
Only reason I asked if it had to be slant 6 or not is I am looking at a few "core" transmissions Wednesday that are like 4 hours away. I want to get at least one as a backup if the 999 falls through. they are V8 transmissions and I wondered if one of those would work is all.
Click to expand...
One other thing for you to consider or research.
If this is a street car, a friend of mine who is also very torque flight knowledgeable tells me there is currently available a higher stall converter that is still equipped with a lockup clutch. I have never heard of that and do not know who makes it, but it supposedly exists. Maybe make some phone calls. This would be great for a street car. Supposedly some new technology.
 
Duane said:
One other thing for you to consider or research.
If this is a street car, a friend of mine who is also very torque flight knowledgeable tells me there is currently available a higher stall converter that is still equipped with a lockup clutch. I have never heard of that and do not know who makes it, but it supposedly exists. Maybe make some phone calls. This would be great for a street car. Supposedly some new technology.
Click to expand...
I dont own a trailer, and it's an hour drive on the interstate to the track, so while all we have done with it the last 2 years is race it its DEFINITELY still a street car.
We would LOVE any leads you can get in that direction!!!!
 
I run a 999 and have over 1000 passes with no issues. Tore it down at 500 and everything was fine. Mods include TF2 kit hot street, blocked lockup circuit with brass plug, Turbo Action S-800 10" 3200 tight converter, everything else is stock. The converter does not have a clutch. I drive 50 miles to the track. 1.65 60', high 11.7 good air, 12.0 hot humid FL.
How to disable the lockup feature on a lockup A-904 or A-727 - Slant Six Forum
s800
 
mderoy340 said:
I run a 999 and have over 1000 passes with no issues. Tore it down at 500 and everything was fine. Mods include TF2 kit hot street, blocked lockup circuit with brass plug, Turbo Action S-800 10" 3200 tight converter, everything else is stock. The converter does not have a clutch. I drive 50 miles to the track. 1.65 60', high 11.7 good air, 12.0 hot humid FL.
How to disable the lockup feature on a lockup A-904 or A-727 - Slant Six Forum
s800
Click to expand...
Did you do the "machine a non lockup stator for clearance" trick too, or does Turbo Action make a non lockup converter that fits the lockup pump and input shaft?
 
motorpirate said:
Did you do the "machine a non lockup stator for clearance" trick too, or does Turbo Action make a non lockup converter that fits the lockup pump and input shaft?
Click to expand...
No machining. The converter is 26 spline and fits. Talk to Paul at Turbo Action and he can recommend the best stall for your combo.

s800
 
mderoy340 said:
No machining. The converter is 26 spline and fits. Talk to Paul at Turbo Action and he can recommend the best stall for your combo.

s800
Click to expand...
Ok sorry I am missing something from your previous post. Are you saying that your trans was a lockup model and is still using the original lockup input shaft with a turbo action non lockup converter.
I believe the spline counts are different between a lockup and a non lockup shaft. Turbo actions description of the converter does not mention the converter working with a lockup shaft.
Did you build the trans yourself or someone else?
 
You must log in or register to reply here.
-

Back
Top