Progmgr, I do intend to use the 6r80. I don't have the motor and trans yet. I will do all my body work probably first and tackle that maybe next summer? Not in any hurry but....
Some rumors are that there is room, that there won't be much room for pedals. I hear that it is very close for pan to cross member clearance. I am not against cutting and welding. FFR only said it won't work because they don't have a driveshaft. Ok so that's not a problem. The next issue is foot room left after its in. I have some ideas on that, including just putting the brake pedal where the clutch pedal is (I Already have to severely mod the pedal box to mount the ABS system master cylinder, and could easily move it over by doing same mods just mirroring the bracket I have pictured). This would allow me to move the gas pedal over some. But the initial measurements I have found online, I'm not so sure the bell housing is any larger than the 4r70. It's longer for sure. The other option is to move everything toward the driver to get farther on the smaller radius. All those, I will tackle once I have it in the car.
Gearing is the final issue. I can attest that the 1st gear ratio is very low. I have a 2015 mustang (with a 2.9L whipple at 13 psi). 1st is so low it's useless on that car. But the close ratio from there up is nice. Rarely does it go to 1st or second unless at a dead stop. I will run a fairly tall tire on 20" rim in the rear (Louisiana roads don't lend well to rubber band tires) and I will run a taller rear gear. Probably in the 3.08ish range.
I know it's a lot to just be able to say I did it, but it's what I want so it's what I set out to do lol.
I'm not to worried about making it fit and work. I'm actually more worried about making the top work removable with the roadster windshield that I have an itch to attemp after reading the hot rod Lincoln thread.....