As some of you know, my build has been based on an LT1/T56 combo. When I bought all those pieces they were relatively current. But I've been so slow to complete the car they are not current at all.

So, moving into the 21st century, I'm thinking about an LS engine. Probably an LS3 crate engine, either the 430 hp or 480 hp version.

The question I have - are the OEM T56 transmissions for the 93-97 LT1 and the 98-02 LS1 the same dimensions, especially the tailshaft housing? What I'm wishing for is knowing whether I can use a 98-02 transmission, or convert my 94 transmission to an LS bellhousing and input shaft, and have the driveshaft and crossmember location remain the same, and with that will the engine fit the engine compartment correctly?

I think it might be just fine - that the additional length of the LS1 bellhousing and the shorter length of the LS1 would cancel out - and the heads would clear the firewall nicely and also have good clearance between the accessory drive and radiator/fans. But I don't have much other than a gut feel.

To be able to put that combo in the car without changing the driveshaft length, shifter hole, and have everything else fit would make the decision to do it much easier.

The other thing I'd like to know, but this is a stretch, is what's the most likely engine mounting adapter plate to use? Stock, 1.5" forward, what?