Newb Questions

I’ve been reading around on a 360 swap and have a few questions.

I have a 74 Dart Swinger Slant 6, my goal is to get a 360 in the car and running, then i can do a “build” down the road when more money comes in and get into new pistons, heads, etc.

My current trans is stamped A904, will this work with the 360? I read I would then not have a need to shorten my driveshaft. With the most popular trans are the 727 and 904, is mine that same 904?

Next question is, my plan is to throw a cam, then obviously header, exhaust, maybe bigger carb and intake. Would my stock 7.25 rear suffice or would I need to look for a 8.75? And would my 904/stock driveshaft work with that 8.75 rear?

Would I be able to install a floor mount B&M shifter with my 904 if I can use it? What does installing a floor mount shifter on a column shift car entail?

thanks in advance all!