12 Valve Cummins cylinder head replacement Competition or street ready and is a performance upgrade Cylinder head. Flows 40 percent more than a stock head right out of the box. The intake ports offer the most velocity of any port we have offered yet. This translates to reduced turbo lag and lowers exhaust gas temps throughout your desired rpm band. Even a stock truck will see an improvement. A thicker deck and casting is used to reduce heat warping and it also is more resistant to cracking compared to a factory style cylinder head. The factory style intake shelf offers more flow to cylinder 1 and 6 versus a factory casting by reducing restrictions in the ports, essentially providing the same thing a side draft intake does. It can be machined to accept fire rings and O-rings.
(98 12 valve may require a bushing for the coolant temp sensor)
Stage 1: Machined for a 1.750″ intake valve and 1.750″ exhaust valve.
Stage 2: Machined for an oversized 1.850″ heavy duty intake valve and 1.750″ heavy duty exhaust valve.
Machining: The head is machined for fire Ring grooves to be used only in the head unless requested call. The fire ring groove is cut for an OD of 4.550″ and a .105 wire. If you have questions please give us a call, we also have the warhead available if you are looking for a heavy competition sled pulling cylinder head.