The key to distributor swaps is to use a distributor with the correct diameter shaft for the oil pump drive. Also pay attention to the thrust load on the distributor, if the dist body or oil pump body is supposed to take the end thrust. Make sure the dist gear is in good shape and not crammed down on the oil pump. Use layout dye to check fitment of gears.

Preaching the Hot Rod Gospel according to the 4-stroke apostles:

Suck, Squish, Fire and Fumes