Tremec

Holley has some interesting stuff for Gen3 swaps in an A-Body. One thing they have now is a bolt in crossmember brace for a TKX swap - https://documents.holley.com/199r12231.pdf

The pictures of the floor cut in the above pdf is really pretty minimal.

Unfortunately I think the part will not work without the matching Holley motor mounts for the Gen3. Their kits says it will fit a 6.4 in the car with the SRV without cutting the firewall. So I think it moves the motor forward several inches and a standard SBM location would create interference between the mount and the brace.

But it does make me think a TKX swap might be able to be done with much less surgery on the floor. Still need a crossmember but maybe not a complete tunnel beyond that??