My head gaskets project is still successful from another of my threads. The intake manifold gasket on the other hand has failed again. I replaced the intake manifold gaskets with the FELPRO gaskets about a year ago and they failed again. The head gaskets are doing fine. I replaced the FELPRO with the FORD intake gaskets. The FORD gaskets have a definate larger thicker O-Ring around the air and coolant ports. It is noticably thicker and deeper around the water jacket. It's been a week now and geewiz, the gaskets are still holding.
It is basicaly a bad design by FORD revolving around the #1 cylinder intake port and the water jacket crossover in the intake manifold being held down by only two bolts with a plastic intake manifold that is susceptible to flex. There should be a bolt between each port opening.

 

From past experience, found it most of the time better to use OEM parts. Don't worry ,they know when they have a problem, and most of the time the change is made without notice. When they decide to correct it , THAT IS !

 

It's been 6 weeks and the new style FORD gasket is still doing it's job holding water in the engine. I know what you mean about OEM parts. Problem is that it's their part that failed to begin with. Then you place your faith in an aftermarket brands product and that fails too. The source of all problems with this engine was plain and simple slopy factory machine work for the head gaskets and one bolt to few for the intake manifold. I guess I trust my ability to do the work to repair the engine subject to the limitations of the repair parts available. For now, all the repairs are working and that makes me happy till something else happens