904 swap

So I now have two 904 transmissions, one from a passenger vehicle and one from a truck. I want to install one of these into my A-body. the truck 904 is usable but has the short tail shaft. The car 904 needs a rebuild before use. Is it feasible to swap tail shafts so I can use the truck 904 in my A-body? I can do mechanical work, but I have never worked on a transmission before, will this require any special tools, skills, etc?