Introducing our Freedom Series cylinder heads for the 6.6L Duramax Each cylinder head is manufactured in our state of the art Freedom Racing Engine shop and is guaranteed to meet or exceed factory specifications. All heads are meticulously inspected, pressure and leak tested, and are equipped with new valve guides, springs, and valve seals. Perfect for the daily driver or towing application, these heads utilize stock valves with a 45 degree angle on the intake and exhaust ports. Now available with no core charge Features New valve guides, new springs, and new valve seals Pressure and leak tested Precision ground stock valves with a 45 degree angle Multi angle valve job Warranty 1 Year Limited Parts Warranty