Intake manifold Not seating properly (?)
I always use black hi-temp on the front and back rails. The last two intakes I pulled I used the engine lift and a carb plate to get the intakes un-stuck. That silicone sticks so well it seemed close to lifting the tires off the ground before I started in with a razor blade! I'm scared of prying that hard on aluminum.
Fwiw I never used the corks- and never had a leak there.