I know bell housing is different but is mainshaft too? I have T56 behind LT1 and though if i can use it with LS1 ???
thanks!

 

The differences I have noticed while helping people pull T56's is that the LS1 front plate on the tranny has mounting provisions for the hydraulic "push" type slave cylinder, while the LT1 has the fork ball, which is not used on the LS1. The LS1 bell housing lacks the mount/studs for the slave cylinder cup, but has a cutout to access the slave cylinder bleed nut.

I am pretty sure the length of the input shaft is different.... you need to verify that, but I'm pretty sure that's the case.

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Fred
94 Formula A3+1: 381/TH400+OD/N2O

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11.513@115.59 on motor; 11.162@127.67, 1.643 60' on a 125-shot. Going with a 275-shot this year

 

Yes the mainshaft(4th gear) is about 1.5 inches longer. The front plate and bellhousing are also different. All else is the same.

 

I can verify that the "midplate" (front of the transmission housing) and input shaft are different (along with the bellhousing, of course). I converted a LS1 trans over for use in my LT1 application.

If you're interested, I've got a LS1 input shaft and bellhousing sitting around, both in excellent condition. Trust me that you don't want to pay dealer prices on these items.

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1996 Impala SS - LT4 396, T56
1996 GMC K2500
1992 Buick Roadmaster Estate Wagon

 

I don't know the design differences, but the brand and supposedly quality (strength) changed with the LS1 version, for the worse.

 

Around '98, Tremec bought out BWA (Borg Warner Automotive), who of course owned Muncie. Production of the transmission was moved from Muncie, IN to Tremec's Mexico plant. This is when the rumors started flying about the LS1 transmissions being weaker than the LT1 versions, despite the fact that they both use the same parts manufacturered by effectively the same company.

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1996 Impala SS - LT4 396, T56
1996 GMC K2500
1992 Buick Roadmaster Estate Wagon

 

Our shop has seen about a 10:1 ratio of broken LS1 T56s to LT1

 

eric bryant i am interested in your bellhouseing and shaft for the ls1 you can email me at mybadbanshee@gmail.com

 

Eric has not visited this site since 1/21/2009. If you want to contact him, try e-mailing him. Left click on his screen name, and the drop down will offer the option to send him an e-mail (if he permits e-mails).

And of course his post is 9 years old..... but maybe he still has the parts.