pull the intake & get a new gasket set & check it as some of the front/rear cork seals are too thick (tall) mockup the intake side gaskets & see what you have for gap (front/rear) & compare that to the cork gasket heights. with that resolved make sure you use some cement in the corners where the sideways ends of the cork gaskets meet the front/rear ends of the main side gaskets & as you know that includes the manifold corners right there also