The later integral head engines will accept the early cylinder heads. But they are not usually compatible with unlead gas. (need hard exhaust seats)
I have done several of these swaps for customers. As uncracked integral heads are unavailable from the local bone yards. My rebuilder suppliers are very proud $$$ of these heads as usable cores are hard to obtain.
The linkages and exhaust have to be changed. If used in an originally integral chassis.