Which Intake manifold gasket

furrystump said
I’m just discussing the transition from intake to head. Not the runner size/shape etc. It is my understanding you never want the flow to impact a right angle surface. So an intake port ever so slightly smaller than the head port is the better way to go. It also helps with reversion because those pulses hit the right angle as the flow tries to reverse up the intake tract. Perfect being exactly the same.

Yup. Certainly YR is talking “big picture”, the entire port/runner from intake plenum to bowl. Not just widening at the gasket surfaces with only short minor tapering/blending creating a shape he is referring to. Going deep, working a smooth radius or contour is part of the gasket matching step, which many here are aware of. Others maybe not, but are now:thumbsup: