6.4 Cylinder Heads in stock, most orders ship within 24 hours.
Our popular O-ring heads start off with a 100% brand new casting made just for us, to our exacting specifications. We have improved several key design flaws with the factory cylinder heads - KDD castings incorporate a higher nickel content and thicker deck surface for a more rigid casting, and hardened alloy valve seat inserts (to prevent cracking of the valve seats like the factory heads are notorious for). We receive our castings bare, then do all the finish machine work in house, including our proprietary O-ring design. We O-ring all of our 6.4 Powerstroke heads because it virtually eliminates the head gasket issues these engines were plagued with from the factory. A receiver groove is machined into the deck surface of the heads and our USA made stainless wire is pressed into the groove - the wire protrudes from the groove applying extra pressure to all layers of the MLS gaskets - sealing combustion pressure in the cylinder. The high carbon stainless wire we use won’t compress or deform over time and is reusable should you have the heads off of the engine for any reason in the future. Our O-ringed heads work with any standard “off the shelf” head gaskets, and don’t require any special machining of the block - just prep the deck surface ensuring the block is clean, dry, and flat. The iron matrix valve guides are diamond honed to size leaving a smooth cross-hatch finish in the valve guide similar to the cylinder bore, which provides superior oiling and wear resistance in the demanding diesel application. We then hand assemble the heads with our new USA made valves and springs to our proprietary blueprint specifications, eliminating sloppy factory tolerances and correcting the poor valvetrain/lifter geometry. We use a quality bonded style valve stem seal so they don’t blow the seals apart like the factory crimped seals do. Kill Devil Diesel cylinder heads are 100% new so there is no core charge or return shipping to hassle with. The heads come ready to install, with a 12-month replacement warranty against defects in quality and workmanship.