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t56 out of a '99 viper

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Old Nov 5, 2008 | 11:19 PM
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Default t56 out of a '99 viper

just pulled one of these out of a viper and was wondering if i put it in a 70 nova behind an ls2 do i have anything i should look out for?? tremec says it should work, ill just need to get the correct slip yoke..it seams to be the same size as a normal t56.

ive had one person say from keisler that the shifter would be to far back and another not even mention that..what do you guys think?

it should would help out the wallet since its a free trans..



thanks!
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Old Nov 6, 2008 | 04:45 AM
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I didnt know that the bolt pattern was the same. Mines a modified F-body transmission from what i understand with the viper mainshaft.
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Old Nov 6, 2008 | 07:21 AM
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I believe you will need a different clutch, different slip yoke, a different bellhousing, and maybe more. It should work, but it's not going to be a plug and play swap.
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Old Nov 6, 2008 | 09:15 AM
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On the bright side of things the Viper trannies are stonger and have more ideal gearing when compared to the F-body version.
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Old Nov 6, 2008 | 09:33 AM
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I have one behind my LS1.. can be done, but a lot of work must be done and mods to the trans.. in the long run, I might be cheaper to by a Viper Spec'd trans that is already setup for GM Engines. For the most part, the T56 is the same trans for all GM, Mopar and Fords, just built to different spec and the tail shaft will be of different configuration as is the front end of it, but the case will adapter to all manufactor (for the most part) parts.

Some areas to be concern on for swapping:
1) Input shaft needs to be changed to work with the Gen III/IV engine / Clutch setup, it is different size.
2) Bell housing and front adapter plate need to be swap for a GM Gen III/IV engine ones to be able to bolt up to the engine. You can get away with using the Viper Adapter plate, the GM bell housing will both up, but the GM Clutch slave will not bolt up and the Viper one is the wrong size for the GM Clutch.
3) Hyd Clutch Slave needs to swapped over.
4) Shifter location is different as is the shift bolt pattern.
5) VSS is different in both size and type of signal (Hall signal)

I have a thread for what I did..
Input shaft was swapped out, used Viper Adapter plate, use GM bellhousing and mod'd a GM Clutch slave.
I used a slip yoke from a old Dodge Van.
https://ls1tech.com/forums/manual-transmission/503808-t56-gm-viper-throw-out-bearing-slave.html
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Old Nov 6, 2008 | 10:31 AM
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Originally Posted by pist0lpete
On the bright side of things the Viper trannies are stonger and have more ideal gearing when compared to the F-body version.

I believe the F-body viper trans is stronger. They use carbon fiber synchronizers and steel 3-4 shift forks as well as the same 30 spline mainshaft. They have a .80 5th and .62 6th as opposed to a .74 and .50 on the fbody shaft i believe.
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Old Nov 6, 2008 | 04:46 PM
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You might just want to look into the Transzilla aftermarket T56 if your are really after a strong T56 for your car/truck. And it should bolt right up.
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Old Nov 6, 2008 | 05:05 PM
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Originally Posted by bczee
I have one behind my LS1.. can be done, but a lot of work must be done and mods to the trans.. in the long run, I might be cheaper to by a Viper Spec'd trans that is already setup for GM Engines. For the most part, the T56 is the same trans for all GM, Mopar and Fords, just built to different spec and the tail shaft will be of different configuration as is the front end of it, but the case will adapter to all manufactor (for the most part) parts.

Some areas to be concern on for swapping:
1) Input shaft needs to be changed to work with the Gen III/IV engine / Clutch setup, it is different size.
2) Bell housing and front adapter plate need to be swap for a GM Gen III/IV engine ones to be able to bolt up to the engine. You can get away with using the Viper Adapter plate, the GM bell housing will both up, but the GM Clutch slave will not bolt up and the Viper one is the wrong size for the GM Clutch.
3) Hyd Clutch Slave needs to swapped over.
4) Shifter location is different as is the shift bolt pattern.
5) VSS is different in both size and type of signal (Hall signal)

I have a thread for what I did..
Input shaft was swapped out, used Viper Adapter plate, use GM bellhousing and mod'd a GM Clutch slave.
I used a slip yoke from a old Dodge Van.
https://ls1tech.com/forums/showthread.php?t=503808
Good info. I've come to the same conclusion, input shaft, mid plate, th400 slip yoke, tailshaft housing, shift rail, bellhousing, and speedo all need to be swapped.

I have a viper trans sitting here that I've been debating on converting.
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Old Nov 6, 2008 | 05:11 PM
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Originally Posted by Shawn MacAnanny
I believe the F-body viper trans is stronger. They use carbon fiber synchronizers and steel 3-4 shift forks as well as the same 30 spline mainshaft. They have a .80 5th and .62 6th as opposed to a .74 and .50 on the fbody shaft i believe.
I believe you may be incorrect about the f-bodies having the 30 spline mainshaft stock. Anywho maybe this thread will help explain the differences between the two and why the viper is stronger (https://ls1tech.com/forums/showthrea...ght=t-56+viper)

Edit: This thread may help as well (https://ls1tech.com/forums/showthrea...ght=t-56+viper)

Last edited by pist0lpete; Nov 6, 2008 at 05:30 PM.
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Old Nov 6, 2008 | 06:05 PM
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Originally Posted by pist0lpete
I believe you may be incorrect about the f-bodies having the 30 spline mainshaft stock. Anywho maybe this thread will help explain the differences between the two and why the viper is stronger (https://ls1tech.com/forums/showthrea...ght=t-56+viper)

Edit: This thread may help as well (https://ls1tech.com/forums/showthrea...ght=t-56+viper)

I believe he meant to say an aftermarket built F-body to viper specs is stronger. A standard F-body does not use a 30 spline and is DEFINITELY not stronger.

The big issue here is that the guy is wanting to save some coin.....swapping all of these parts will definitely not save coin and you can buy a T56 that will work without modification for a lot less.
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Old Nov 6, 2008 | 08:41 PM
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yes saving some coin would be nice...i chatted with keisler last week and they mentioned that the viper trans would be a good way to behind the LS2 however they are on backorder and for them to rebuild mine would be more than being it already to go...i didnt realize i needed to change the main shaft..

keisler quoted me 5k for everything including the viper trans....which he was saying it was the only way i could go with an LS2...I think the more I talk to these guys about tremec's I get more confused..lol

thanks guys for the info i figured you guys would know...if you see a viper trans for sale youll know who it came from..lol
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Old Nov 6, 2008 | 09:20 PM
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Originally Posted by strtlegal
yes saving some coin would be nice...i chatted with keisler last week and they mentioned that the viper trans would be a good way to behind the LS2 however they are on backorder and for them to rebuild mine would be more than being it already to go...i didnt realize i needed to change the main shaft..

keisler quoted me 5k for everything including the viper trans....which he was saying it was the only way i could go with an LS2...I think the more I talk to these guys about tremec's I get more confused..lol

thanks guys for the info i figured you guys would know...if you see a viper trans for sale youll know who it came from..lol
I'm running a stock M12 ratio T56 trans behind a LS2 in my 2005 supercharged GTO 505/502 at the rear wheel!. At 20k miles I can tell that I am stressing it a little but by no means am I having any trouble out of it.

You can have a bulletproof T56 without using viper internals for under $3k. When I say bulletproof, I mean 700 hp so not completely indestructible, but more than what you will probably ever push through it.
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Old Nov 6, 2008 | 11:12 PM
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yes im not planning on going past 500 at the crank..

my only issue is buying the trans for 2,300 then buying all the other goodies that goes along with a automatic to manual conversion...

do you guys have recomendations on people in the bizz to deal with??

darkhorse performance, amp, keisler and classic 5speed are the only ones i know of.
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Old Nov 7, 2008 | 04:53 PM
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Originally Posted by pist0lpete
I believe you may be incorrect about the f-bodies having the 30 spline mainshaft stock. Anywho maybe this thread will help explain the differences between the two and why the viper is stronger (https://ls1tech.com/forums/showthrea...ght=t-56+viper)

Edit: This thread may help as well (https://ls1tech.com/forums/showthrea...ght=t-56+viper)

Yeah i meant a Viper spec Fbody trans is stronger than a stock Viper transmission. D&D built mine.
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Old Nov 7, 2008 | 05:03 PM
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Originally Posted by strtlegal
yes im not planning on going past 500 at the crank..

my only issue is buying the trans for 2,300 then buying all the other goodies that goes along with a automatic to manual conversion...

do you guys have recomendations on people in the bizz to deal with??

darkhorse performance, amp, keisler and classic 5speed are the only ones i know of.
RPM transmissions. They are sold by some of the vendors here.

If you are keeping it under 500 at the crank, I'd look for a low mileage stocker on e-bay and just use a LS7 clutch.
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