When comparing this head to other aftermarket heads you MUST compare the standard features that we feel are necessary given what they are intended to be used for. We assume when a customer is looking to purchase a cylinder head at this level, nothing but premium parts are to be used. When comparing to other available heads please note that this head comes standard with:
- Premium Alloy Steel Guides
- Hollow Proprietary Stainless Steel Intake Valves
- Premium Alloy Stainless Steel Exhaust Valves
- Precision Machined Single Groove Locks
- Tool Steel Retainers (Prefered choice over titanium for strength and wear)
- PSI 1515 Beehive Design Spring Capable of 650 Lift (Heads are assembled to your cam specs)
- All Heads Surfaced and Quench Cut When Required
Compared to the 392 Apache head, the 6.4L HEMI Big Gas cylinder head looks very similar, but the these heads are cast using specific tooling designed for heavy duty application. The Apache head is a 319 alloy while the HEMI Big Gas head is a premium heat-treated 356-T6 alloy, giving it higher thermal conductivity and improved elongation (one of the measures of an alloy's strength). Of note are the differences in the valves. The Modern Muscle valves are a custom proprietary valve with a thicker cross section for higher horsepower applications. The intake valves are a stainless high-temp hollow stem valve, and the exhaust valves are solid type premium stainless alloy. These Modern Muscle valves are used in 1500+ horsepower turbo applications.
The following are some improved features of HEMI Big Gas heads over the Apache heads:
- Better material for boost
- Increased stiffness for boost
- Improved water jacket design over any previous head design for higher power levels
- Custom CNC porting by Modern Muscle Performance
- Multi angle valve job, and blended
Be sure and ask about installation, and professional calibration here at Modern Muscle Performance!
We do not recommend this head or any other head of this valve size or bigger purchased for a small bore application (5.7L or 5.7L based strokers).
Due to valve sizing and placement, please contact us to review your build to make sure you have adequate piston to valve clearance both in depth and radial.