Comp Cams XD-A Adjustable Pushrods

The patent-pending Comp Cams XD-A™ Adjustable Pushrods incorporate a top section that slides two inches inside a wider bottom section, with one or two shims captured in-between. Proven to 9,000-plus RPM in solid roller LS applications, the system provides a 90-percent increase in bending stiffness for enhanced valve train stability. It also allows for lightening of a rocker arm system by 30-plus grams on the backside by removing the adjuster and required support area for threads and seating. The use of lighter rockers (such as the COMP Cams® SPR™ Radius Tip Rocker Arms) with XD-A™ Adjustable Pushrods allows higher RPM to be achieved by creating a much more dynamically stable valve train system. The pushrods are designed especially for engines with low-mass rocker arms and a light valve train with drop-in fitment in LS engines. They can be adjustedover a range of .172" in .004" increments with shims, sold in sets of 16 by thickness or as a 240-piece set containing all available thickness options. Top sections are available in 0/200" increments for coarse adjustment and work with hydraulic and solid roller camshafts.