Yes, Most of my experience with 216s is trucks & pickups. I had a completely stock '49 pickup with a 3 speed column shift. I put a 4 speed truck trans in it that was built for open drive line. I changed the rear mount that bolts to the case which also made it work with closed driveline. Later I bolted a '58 235 from a car to that trans. A 261 that I pulled from a '40 coupe with 3 speed column bolted into my '40 pickup with the stock 3 on the floor. There were length difference with the 235-261 that caused radiator clearance issues but no transmission issues. I pull a 216 from my '48 Fleetline and installed a 235 that came out of a '52 business coupe. I don't know who put it in there. When I swapped out the vacuum assist trans in the '48 for a '53 car trans I had to shorten the closed driveline 2 1/2" Could any of this be difference in car & truck bell housings? Yes the 230-250 are longer (no longer than a GMC) but a small radiator move fixes that. Mounts are not hard. The crossmember could be pain.
I agree with running what is there if possible and it can be made into a fun driver, at least at first. Get it running, have some fun, get to know the car, and learn about the options and what there require. There is plenty there to keep him busy for quite a while.
