I can drop it if I have help picking it up first.
Do you mean can you use a non overdrive transmission? The ECU does not control the transmission in these cars. The transmission is not electronically controlled , so yes. That’s why I listed the non OD automatics as possible HD replacements.
What about sub frame connectors... Real beefy and weld in. Otherwise you will twist up that uni-body!
I think I'd do trailing links to the added tourque at the rear wheels could twist them up to. You may also rear end gears, drive shaft, and axles, especialy if you're putting a blower on it.