Slant six info

Just got. 65 barracuda slant six from original owner,engine is .60 out already,head is cracked,looking for info on interchangeability of the slant six,been told 60-67 only blocks? As I understand this is a solid lifter engine,will the later 225 engines bolt in to the existing mounts and if so.? What else am I in store for ? The Trans is a 904. Thanx