Quick Ship SKU #: MP-D-141-Dmax Manton Tool Steel Roller Rocker Arm Assembly 01-23 GM Duramax

Are you ready for the strongest and smoothest operating roller rocker arms for your Duramax? Manton offers up this complete kit that will surpass your expectations and allow you to properly build your engine for extreme power and reliability.

With more racers hitting the tracks every weekend and power levels continuing to rise, Manton felt it was necessary for an aggressively designed roller rockerarm system. Changes have been made in several areas to improve overall performance of the valvetrain and help increase service life.

With minimization of deflection being the main concern, they incorporated one of their proprietary tool steels into the rockerarm bodies. Further, they use a multi-stage heat treatment process to core harden the bodies. Then, the bodies are nickel plated to prevent any contamination. To aid in lashing the valves a simpler process, they have broached the adjusting screws to accept an allen wrench, instead of the slot for a flat head screwdriver. Manton's Top Fuel proven pin and roller combination on the valve side are integrated, which reduces side thrust on the valve by removing the scrubber from the rockerarm. Going away from the shoe style rockerarm required a conversion of the geometry theory, allowing them to keep the factory rockerarm ratios and utilize the existing camshaft.

During the development stage of this rockerarm, it was determined that the aluminum head could use a girdle to help strengthen the head against deflection caused by cylinder pressure. Thus, Manton incorporated a heat treated 0.250 wall chromoly rockerarm shaft, to provide the needed support. While aiding the cylinder head, it also features full time oiling grooves. This groove prevents the rockerarm from shutting the oil pressure off to the pushrod as it starts to open the valve, like with an OEM style shaft. As with all heavy wall shafts from Manton, they've used a threaded shaft plug on each end, to prevent any worn or poorly fitting press plugs from compromising the seal.

Furthermore, Manton includes higher grade ARP twelve point bolts with washers for a secure fit. To match these bolts, you'll also get 12 point ARP poly-lock jam nuts to keep everything secure. Overall, you'll gain a massive upgrade in dependability to the powertrain as a whole.