Transmission threads. Auto vs Manual

I think the manuals tend to have a little easier swap without cutting up the floors. Or there seem to be more options that limit the damage at least. You can run a stock 4 speed with zero mods to the floor or the Passon 5 speed (assuming they are still making them) if you want a drop in OD. A Gear Vendors unit is another way to get OD without floorpan mods. I think the TKOs will fit without much cutting, but I just don't care for the gear ratios in them so I didn't look that close.

Any modern automatic just seems to take up a lot of space. I suppose you might be able to stuff something like a 42RH or whatever it's called (basically a 904 with an OD section bolted on the back) with minimal work as it's basically just a slightly longer 904, but the way the tunnel narrows at the back I'm guessing you'd still have to do something.