I found a pre ls1 t56 for $600. I would like to put it behind my 70 chevelle 454 which currently has a M20 behind it. Has anyone done this conversion, I would like the car to remain stock looking with it's bench seat.

Ive done it, what all would you like to know?
http://forums.corvetteforum.com/showthread.php?t=1575584&highlight=T56

Id recommend a ministarter, too.
Keisler has a retrofit kit which is MUCH simpler than this and allows you to use your clutch linkage, etc. May want to check with them before you buy anything, this was done long ago before all this stuff was out.

I would like to use my existing clutch and flywheel, it has less than 1000 miles on it. I would also like to use the stock clutch linkage. thanks for your info.