I put a 292 in my '64 with a 2 barrel on top. I was looking to see if I could pull a few more MPG out of her and went to a couple "stove bolt" sites. It seems we can get more MPG if we allow the motor to breathe better. There is a trick called "lumping" the heads where you get rid of a "step" in the exhaust chamber. I breeezed over that as it entails some head work that I don't want to do now but, they also say that a 500 cfm 4 barrel on an Offenhauser intake can help as well. It will help her breathe on the front side.
My question is have any of you done this?? I would be willing to give it a go but, I don't think it will fit in a gen 1 doghouse......unless the Offy manifold is much closer to the head.
IF any of you have put on a 4 barrel, please let me know about what modifications you had to do. If I have to cut out the dog house, it's not going to happen.