Check out the casting and machine work from another perspective, on top. These guys are all ready for screw-in studs and final assembly. Why mess with the expensive rework of factory cylinder-head castings when you can install RHS Pro Action heads right out of the box? One word of caution-Marvin McAfee of MCE Engines subscribes to a strict policy regardless of the product. "Trust, but verify..." he tells us. Never install anything right out of the box without inspection.