1977 350 Chevy motor. Installed intake manifold and it leaked coolant between the intake and head above the second intake bolt on both sides. It's not coming from the bolt..it's above the bolt .Took off manifold and redid everything again. Used gaskets on the side and high heat silicon as the front and back gaskets. Put a little bit of silicon around each water port ..Still leaking in the same spots...any ideas? Have done several motors the same way and never a issue..something is wrong and I just can't put my finger on it...