Small block Trick flow heads

'63GT said
Exactly right. In fact, the ports were raised .100 to prevent a dip in CSA.

Pittsburgracer, did you see how badly out of whack the OE W5 holes were drilled? They didn't even match the gaskets shipped with the manifold. LOL

Ya I see that. You should see some of the Cometic Gaskets I got for my 360-1 heads. Right from Cometic even after two attempts and two or three phone calls. Pathetic with a capital P