I have 2 B4B's one is an orignal off a stage 2 car and the other is a later one set up for a Q-jet or holley. Is there a difference in flow between them? Is one of them casted better than the other? Thanks for all the help.
Most likely the only real difference would be in the height of the lip were it bolts to the heads. The '72 and later heads have A.I.R. holes drilled in them to pass emissions testing. The manifold might be cast to cover them up, as opposed to an earlier manifold which should have the lower lip. Now that I've answered that, I should get the unused B4B, right ??? Just kidding. The other thing that may be different is a GM part# on the stage 2 piece.
I'm running 71' stage ! heads so I don't think the flange is an issue. The carb spot doesn't matter because I'm running a Holley 850Dbl. pumper. Just wanted to know if there was a flow difference? Thanks
