Yes any 1965-79 Pontiac 326, 350, 389, 400, 421, 428, or 455 will bolt in with minor parts swapping. (you may need adapter plates as already mentioned) and you may need to swap front timing chain cover to match up with your existing accessory drive pulleys. Pontiac changed front covers & water pump designs a couple of times from 1965 to 1969. After that the timing covers and water pumps are pretty much the same.