I'd look at a GM 3 speed box from something like a corvette

Yeah I'd agree the best answer would lie in a yank box.

Something like the TH350 would be cool with a manual shifter and a transbrake. You'd have to get quite a high stall torque converter though. Most prob only stall up to 3500-4000rpm.

If its strip only then a 2 speed powerglide could be another option and is a very common drag box.

Although being an auto box you do actually shift them manually.