FEL-PRO 17211 HEAD SET GM (Chevy) 4.3-Liter V-6 with Balance Shaft. (This kit for engines with 12-bolt intake manifold), Head set contains: all gaskets and seals necessary for a valve grinding job, including cylinder head gaskets, valve cover gaskets intake and exhaust manifold gaskets and valve stem seals. Note: Valve cover gaskets are for center bolt Composite Valve Covers.