The powerful AFR 220cc intake port small block Chevy angle plug cylinder heads are available in three stages of performance. The Race Ready version features 100% CNC ported intakes while the higher flowing Competition version features 100% CNC ported intakes with greater detail. Both come with 100% CNC ported 76cc combustion chambers and 80cc exhaust ports with a 3/4" thick head deck (ideal for nitrous or blower applications). In addition we also offer the "as cast" Stage 1 heads for 220cc performance on a budget. Standard valves are 2.100 intake and 1.600 exhaust with AFR's hardened ductile iron interlocking valve seats. The exceptional flow characteristics, 23Á valve angle, and standard valve spacing make this the perfect head for 350 to 434 cid engines in drag cars, spring cars, and late model oval trackers operating between 4500 and 8500 rpm. The 220cc heads are available in either standard or spread port exhaust. Dual valve cover bolt pattern is standard. The exhaust port is raised .400 over GM L98 heads. Chevrolet Small Block - 220cc Competition CNC Strip Porting - 65cc Combustion Chambers, Plug - Bare Heads