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CNC Ported GM 317 Casting

CNC Ported GM 317 Casting


CNC ported GM 317 Castings

228cc intake runner, 84cc exhaust

72cc chambers

sold in pairs

  • General Recommendations

    Wilkes Performance assumes no responsibility for damage if the end user builds an engine without properly verifying he has enough piston to valve clearance (depth and radial clearance both checked). It is recommended for a minimum depth of .080″ on the intake valve and .100″ on the exhaust with a radial clearance of .030″ minimum around the perimeter of each valve.  It is the customers responsibility to verify proper piston to valve clearance.

  • CNC Porting

    On occasion a 100% CNC ported head might have casting areas left “as cast”.This is due to core shift and this in no way affects performance.

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