Intake Leak

Go to a craft store and buy some poster board that's around .060 thick. A light color works best. Take a new gasket and trace it, mark the manifold bolt holes and use a gasket punch, don't cut any water or intake ports.

Install manifold with the poster board and torque to 40 ft lbs in the FSM pattern. Do not use locator pins or the cork rail gaskets.

Remove manifold and look at the poster board crush. You can measure with dial calipers.
If the crush looks good you may have a bad valve guide or seal, and possibly a crack in the intake port.

I always use a 1/4" bead of permatex ultra black on the block rails and let it setup overnight. Toss the cork in the garbage.