
- Battle proven, proprietary O-Ring setup to eliminate head gasket failures.
- Reinforced injector bores to prevent cracking
- Hardened valve seat inserts to prevent cracking.
- Heavy Duty iron matrix valve guides for long life
- 100% new heavy duty castings made to KDD's specs, machined in house from start to finish on state of the art CNC equipment
- 25% thicker deck surface increases rigidity for superior head gasket retention.
- Blueprinted to proprietary valvetrain geometry, for proper valve recession for maximum reliability and longevity.
- Assembled in house with new USA made high quality valve springs, retainers, locks, valve stem seals, freeze plugs, glow plug sleeves and injector sleeves.
- The same industry leading O-ring design survived Diesel Power Magazine’s DPC torture test, claiming victory in 2016 and 2017.

Our popular O-ring heads start off with a 100% brand new heavy duty 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). 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.
We O-ring all of our 6.0 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[...]
Our popular O-ring heads start off with a 100% brand new heavy duty 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). 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.
- Battle proven, proprietary O-Ring setup to eliminate head gasket failures.
- Reinforced injector bores to prevent cracking
- Hardened valve seat inserts to prevent cracking.
- Heavy Duty iron matrix valve guides for long life
- 100% new heavy duty castings made to KDD's specs, machined in house from start to finish on state of the art CNC equipment
- 25% thicker deck surface increases rigidity for superior head gasket retention.
- Blueprinted to proprietary valvetrain geometry, for proper valve recession for maximum reliability and longevity.
- Assembled in house with new USA made high quality valve springs, retainers, locks, valve stem seals, freeze plugs, glow plug sleeves and injector sleeves.
- The same industry leading O-ring design survived Diesel Power Magazine’s DPC torture test, claiming victory in 2016 and 2017.