PRC 237cc CNC Ported LS Cylinder Heads

Current Stock:


Precision Race Components All New Cylinder Head Castings Completed With 237cc Runners For Larger Cube LS Based Engines.


  • 237cc Fully CNC Ported Intake Runners
  • 85cc Fully CNC Ported Exhaust Runners
  • Big Bore Chambers Designed For 4.010" Bore+
  • PRC Platinum Spring Kit Rated To .650" Lift
  • 68cc CNC Machined Chambers
  • 2.100" Intake / 1.600" Stainless Valves
  • Factory Rocker Friendly!!*

The all new 237cc cylinder head is custom designed for larger bore engines looking for max power out of a cathedral port layout.  The new 237cc port has been flow bench tested to flow over 340cfm & can support 4.010"+ bore street or race engines.  Engine dyno testing has shown these cylinder heads support over 650 flywheel horsepower in 408cid applications.

Flow Data:

4.030" Flow Plate - No Exhaust Pipe


Intake Flow 


 Exhaust Flow



 66 cfm


 57 cfm



 147 cfm


 117 cfm



 225 cfm


 170 cfm



 284 cfm


 206 cfm



 325 cfm


 227 cfm



 334 cfm


 235 cfm



 339 cfm


 241 cfm







*All aftermarket cylinder heads feature bronze guides. Stock rocker arms will cause increased guide wear in applications over .600" lift.  Roller rockers can help to reduce this wear.