Since I've already swaped in a lt1 T56, I was hoping to keep it when I swap in the LS1 this winter. I know there are differences between the tranny's, but is there a adapter plate available or something?

 

Nope, you have to swap the bellhousing, front plate and input shaft since it is a different spline on the clutch

 

couldn't you just use a different clutch?? and is the bell pattern different?

 

The bellhousing is completely different between the two and the pattern is different if I'm not mistaken, biggest thing is the input shaft, by the time you paid someone to put the input shaft in that would fit a clutch for a LSx based SBC you would be better off buying one made for it the motor to begin with.

 

I've already been down this road... I used to run a 355TPI with a T56 behind it. I now went to a LS1/T56. I wanted to try and use my old LT1 T56 tranny but I would have had to swap the front plate, input shaft, bellhousing, flywheel, clutch assembly, and slave cylinder. Its just not worth it. I decided to sell that old T56 and the LS1 auto tranny and just buy a LS1 T56 tranny instead.