The GM trans from what I remember doesn’t require cutting up the tunnel. BUT.....
The required parts to swap it in and associated parts to modify (IE; driveshaft) make the swap expensive vs a factory OD or other manual transmission “kits” that do the same thing.
What is the final OD ratio of the transmission?
Size of engine and the cam specs?
The 4l60 and 4l80 does. (350 and 400 turbo's are quite large.) The 200's don't but they are weaker than our 904's unless you build he heck out of them. A street stroker would work fine with a 904 overdrive that has been purposely built.
