The 502/502 camshaft uses the stock lifter spider and guides. We used Fel-Pro gaskets and ARP fasteners to put the engine back together. This power-level engine would be fine with ARP head bolts, but we knew we'd be pushing the limit with our final version of this engine, so we opted for the studs. The Signature Series aluminum rectangle-port heads have 2.19-inch intake valves and 1.88-inch exhaust valves. The intake ports are between 300 and 315 cc, and the exhaust ports are 110 cc. The combustion chambers are 118 cc.