Freedom Series Cummins Performance cylinder heads. Each head is manufactured in our state-of-the-art cylinder head machine shop and guaranteed to meet or exceed factory specifications. All heads are inspected, pressure checked, decked, painted, and ready for installation. Plus, the 11 screw in freeze plugs ensure you'll never worry about a coolant leak under the valve cover again. Perfect for a daily driver or heavy duty towing, our Street heads are rated for use up to 700hp. If your engine configuration is exceeding factory RPM limits a Performance Series head with higher valve spring rates is required. Freedom Series Street heads Include: 11 Screw in Freeze Plugs (eliminates coolant leaks) Hardened, oversized press-in valve seats New Cummins valve springs New valve guide liners Head gasket not included. We recommend the use of Cummins 3977063 head gasket. FOLLOW ALL INSTALLATION INSTRUCTIONS - Valve lash required. Back off adjusters on rocker arms or damage will occur to the cylinder head.