1972 340 testing by Nick

I'm not sure how much the extra gasket helped. I'd read in a couple of different articles that the stock 72 manifold inhaled as well as any aftermarket. They said the best mod would be the LD-340 just for the sake of a 30 pound weight savings. I'm sure I have the magazines in a box somewhere. That said, I did have my plenum machined down for the same effect and also have an extra stock manifold.