25534446 Large Port Vortec Bowtie Head Assembly
? Completely assembled, ready to bolt-on
? Improved air flow (281 cfm @ 0.600")
? 225cc intake ports
? 77cc exhaust ports
? 65cc combustion chambers
? Use Fel-Pro? P/N 1470 exhaust gasket (minor trimming may be necessary)
? Bare head P/N 25534445, available separately

These heads are assembled with the following components:
12363757 Intake Valves
10212808 Valve Spring Retainers
12363758 Exhaust Valves
10212810 Valve Stem Seals
12551483 Valve Springs
24503856 Valve Locks
12552126 3/8" Rocker Studs