What is the difference between the SOHC and DOHC intake manifolds?
The DOHC’s intake manifold is made from cast aluminum, which means that it can be polished and ported to match the head. Even if headwork is not planned, it is recommended that the intake manifold runners be polished or extrude honed inside to remove casting roughness. The intake manifold is much easier to remove and polish than the cylinder head. SOHC owners are at a disadvantage, except for a few lucky ’96 m/y cars. The SOHC’s intake manifold is made from plastic, which cannot be modified this way. However, due to a supplier problem early in the ’96 m/y manufacturing run, a small number of SOHCs got an aluminum intake manifold which can be polished and ported. Oddly enough these were painted black to match the plastic piece rather than left natural metallic like the DOHC manifold. This is one reason why more high-performance parts are available for the DOHC. The SOHC’s plastic intake manifold does have some advantages, however. In its stock form it is smoother inside than the aluminu
