This universal aluminum valley plate is designed for use with Chevrolet 18 degree cylinder heads. It can be used in conjunction with dedicated two piece manifold spiders, existing one-piece intake manifolds which have been properly machined for use as a dry manifold or fabricated manifold designes. The valley assembly consists of the following pieces: the vally plate P/N 24502652, the inspection cover P/N 24502651, O-ring material, and eight retaining bolts. The valley plate has cast-in integral passages to equalize coolant flow from the front and the rear of the cylinder heads. Fits heads dated June 1996 or later.