Forgot to add....make sure you check the port match on these
manifolds.....we used those Earl's gasket sets with the inserts and they havent leaked in over two years. However, we did find
that the manifolds missed matching by about 0.100 inches in the vertical direction on a set of aluminum fast burn heads. We have a set of the Corvette manifolds to mount on a set of Vortec heads but we havent tested the port match yet.

Also, the tubes around the mounting holes are a pain but they do move the bolt head out and make it easier to wrench. Manifold studs are too short if you leave the bolt tubes on.

mike in tucson