Easiest install for a SB OD, auto trans.

I'm sure the biggest issue is clearing the floor, some work there may be required, as is for putting a Mopar OD in an A body

Transgo has an all manual VB kit for those trans, if you get an electronic one, so that would eliminate the shifting electronics.

For all of them, hydraulic or electronic, the converter lockup and OD is 3 pins. You feed 12V to I think the center pin, and then grounding the other two gives you the converter lock and OD shift.