What transmissions will work with this?

What are you trying to do? Get better take off gearing? Overdrive? Manual? That info is necessary to give any kind of opinion. I have a fairly well built 318 with a 904 behind it now. Nothing wrong with a 904, but I need overdrive due to 4.10 gears, so I am changing mine. Otherwise, the 904 has great gearing and is pretty darn strong.