Smallblock intake manifold shootout.

I have a LD340 intake on my 340.

I remember talking to an Edelbrock tech guy back when they first introduced the Performer RPM manifolds. He told me that Edelbrock seriously considered simply reintroducing the LD340 instead as they were pretty much comparable to the new release.

I certainly understand the advantages of the Air Gap models though. (Blocking the heat crossover plus using a 1” phenolic spacer is pretty important if you don’t have the Air Gap.)