Not a bolt-in swap. Many changes to side mounts, modern bellhouse, tranny tail mount, maybe radiator moved ahead, not worth it. Later 235's will fit with waterpump change, can get speed parts from Cliffords for them. Check back in forum's, there is a string of articles on this swap if you do search. About the same stuff you would have to do for a V-8 swap, might as well do that for all the trouble.

Keep the six, buy a different car for a "Hot Rod"! :p