Cylinder Head Porting Store » Engine » Cylinder Head Porting Cylinder Head Porting Cylinder Head Porting 4 or 5 Valve $400.00 — $425.00 Valve Select an option 4 Valve 5 Valve 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 25 30 40 50 75 100 Cylinder Head Porting 4 or 5 Valve We modify the intake and exhaust ports to speed up air flow. A good race engine starts here