The biggest problem we find is the seats in the manifold are at diffrent depths.Set the manifold in place and probe each hole in the intake and head for proper length.Do not bottom the bolts in the head as you may pull the threads.The problem with studing the intake is the angle causes binding when trying to install the intake manifold.We usually use two long bolts at the front and back outside corners of the manifold and just start the threads as we lower the manifold to properly position it,then we start all inside ones.