Edelbrock Intake Manifold Install
Look at your intake carefully. The first passages on both sides of the front of the intake is the water passages. The center passage is an exhaust crossover. This heats up the intake for cold weather climate. If you live where there are mild temperatures you can block it off with the metal provided with the gaskets. Check out Fel-Pro 1204 intake gaskets. Looking at the pictures it looks as if someone tried to plug the rear ports of the heads. Also the center exhaust cross-over looks as if it was plugged. This wasn't necessary. You install the gasket with a thin layer of sealer around the water ports front and back. Some gaskets provide the metal to block the crossover or the metal will have holes so it can be used. If you don't use the metal the exhaust will eat thru the gasket and leak.