The bellhousing will be part of the replacement auto transmission. Lots of options depending on overdrive or not.
TH350, PG, TH400, 700R4, 2004R will all work. The last one we did was on a 64, the rear crossmember was removed
and an aftermarket replacement was installed for the rear mount. Will need a flex plate, kick down cable, and an oil cooler
either remote or part of a replacement radiator. A driveshaft modification will also be required.
Fred