PRC 247cc CNC Ported Cylinder Heads

Precision Race Components all new cylinder head castings completed with 247cc runners. For 408 cubic inch and larger applications with 4.03"+ bore sizing. MADE IN THE USA!! CAST IN THE USA!! MACHINED IN THE USA!! Features: 247cc Fully CNC Ported Intake Runners 84cc Fully CNC Ported Exhaust Runners TSP .660 Spring Kit w/ PAC Valve Springs & Titanium Retainers 68cc CNC Machined Chambers CHE Bronze Guides 2.120" Hollow Stem Intake Valves/ 1.600" Stainless Exhaust Valves Factory Rocker Friendly!! The all new 247cc cylinder head is finally available for customers looking for the pinnacle of LS cathedral port performance. The new 247cc port has been flow bench tested to flow over 360cfm. Flow Data: No Exhaust Pipe LIFT INTAKE FLOW EXHAUST FLOW .100" 66 CFM 57 CFM .200" 147 CFM 117 CFM .300" 228 CFM 170 CFM .400" 282 CFM 206 CFM .500" 321 CFM 227 CFM .600" 343 CFM 235 CFM .650" 355 CFM 241 CFM .700" 360 CFM 245 CFM