I have a problem. Was gonna use an offy intake on my current project. I just realized today that the offy intake won't work on 73 heads. I need to make this car run asap. Will a 75 intake work on 73 455 heads? Help anyone? Thanks, Tony
IIRC... the heads' intake flange and a bunch of other stuff changed with the 1971 (1972?) year, so no, the two are not interchangeable. So youre back with the 75 intake on the 73 heads. There was a few changes along the line for changing smog requirements back then, including no EGR valve, the introduction of the EGR in about 73 I think and then some other internal passages (heat cross over etc) that the general runner wont ever notice. I believe theres block off gaskets to use on the smog heads with an earlier intake. I wouldnt trust it though as a a lot of stuff happens right there, water, intake mix, heat from exhaust crossover etc... These pics show some basic early / late intake differences... Along the top of the mounting intake flange is a cast-in pipe for the A.I.R. system. The others show the difference in the heat crossovers... Also, the bolting sizes changed from 3/8 to 7/16 threads...Want to sell the OFFY?ws
The easiest thing to do is plug the AIR holes. The thing to do is pound some brass in them. Also plug the crossovers with some freeze plugs
