The Ford intake manifold gasket should last the life of your engine. This is not an auto part that generally wears out or needs replacing unless the top of the engine is torn apart or repaired. This includes not only total engine overhauls but also when a head gasket or intake manifold are replaced. The intake manifold gasket is used to seal the connection between the intake manifold and the cylinder heads on the Ford engine. This has to be a perfect seal or the air to fuel ratio going into the combustion chamber will not be correct and the engine will be running too lean. The replacement of the Ford intake manifold gasket requires the heads to already be in place. All of the old gasket material must be removed so nothing but a smooth, clean surface area on the heads and intake itself are visible. This is the only way to make sure there is a good seal with the new intake manifold gasket on your Ford engine. Before the intake manifold gasket is put into place, the surface where the intake ports on the head along with the intake ports on the manifold have to be checked to make sure they are flat. This can be done with a straight edge by the owner of the vehicle. If there is any warping of any surface, it has to be machined smooth before your engine can be reassembled. If this is not done, a chance of obtaining a good seal with the new intake manifold gasket is unpredictable. While the gasket can compensate for a very small amount of warping or unevenness, it is not desirable to have any on your Ford engine.