Sierra 18-4486 High Performance Cylinder Head
Sierra 18-4486 High Performance Cylinder Head, Sierra 18-4486HP High Performance Cylinder Head All cylinder heads are new castings; Complete assemblies with new stainless steelvalves; Hardened steel exhaust seats, valve springs, valve locks & retainers; High performance screw-in rocker arm studs; Fits: Vortec GM small block 5.7L high performance; CH350CA: 5.7L Late model vortec 350(906GM casting); 64cc combustion chamber, 172cc intake runner; 1.94 intake valve, 1.50 exhaust valve; Late model bolt pattern 1996 and Up with a perimeter valve cover; Direct replacement for late model vortec heads;