well the 69 have a 11 bolt pattern water pump and my car has a 8 bolt. i meant as far as peformance. i am trying to piece together an engine or buy one complete. i want a 400. should i get a 68 400 motor or a 69 400 motor? and then which heads are the best to put on a 400. its just with so many choices like gto. catalina, lemans, firebird, GP and others to get motors from what should i get.and then there are so many head choices and intake manifold choices i just dont know what to get.???? when getting a q-jet carb should i get the correct year for that motor? i dont have the money to buy everything in one shot it will be bought piece by piece which is why i was asking? i want to build something with 350/450 RW hp, running on pumps gas!