KDD O-Ringed Cylinder Heads Features & Details: Track tested, proprietary O-Ring setup. 32 Tungsten Carbide hardened valve seat inserts to prevent cracking. 32 press in iron matrix valve guides, honed to size for superior lubrication retention and ultimate longevity. Upgraded heavy duty casting, thicker than OE. Pressure tested and vacuum checked. Blueprinted to proprietary valvetrain geometry, to alter valve height and valve recession for maximum reliability and longevity. New USA made high quality valve springs, retainers, locks, valve stem seals, freeze plugs, glow plug sleeves and injector sleeves. Valve spring pressure is tested and balanced ensure consistent spring pressure across all valves The same industry leading O-ring design survived Diesel Power Magazine’s DPC torture test, claiming victory in 2016 and 2017. Order comes as a set (2 heads) Description: KDD O-ring heads start off with a 100% brand new heavy duty casting made just for us, to our exacting specifications. 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). Our 6.0 heads have more material around the injector bores, and reinforced injector bolt holes to eliminate cracking in the injector bore. We receive our castings bare, then perform all finish machine work in house, including our proprietary O-ring design. O-ringing the heads 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. KDD 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. No Core is required. The heads come ready to install, with a 12-month replacement warranty against defects in quality and workmanship. **Heads DO NOT come with head gaskets. We recommend OEM, Fel Pro, and Black Diamond. DO NOT USE BLACK ONYX** **No core charge or return shipping as cylinder heads are 100% new** **There can be a 3-4 week lead time before shipping**
