i had a edelbrock 340 victor on my small block without any issues then bought a speedpro chinese air gap manifold and put it on but it ran like crap, possibly an air leak in the valley somewhere so I bought an edelbrock air gap and replaced it and have not had any issues ever since. I think the chinese manifold did not have the correct angles on the intake surfaces as I have never had a manifold leak air or coolant before. the quality control of those manifolds appear to be suspect. Change the manifold now!
