These lightweight alloy aluminum blocks are not a brittle and weak cheap block found elsewhere, but rather high density aluminum cast blocks with steel 9/16" or the H.D. 5/8" center pins, and bushed holes for strong, reliable operation and accurate axle locating.

Installation of these neat little blocks allow you to accurately and precisely adjust the forward and aft attitude of your rearend, as well as side to side attitude, ultimately fine tuning your front to rear alignment. The application of this block easily allows the elimination of dog-tracking. Spring and frame mis-alignment can be compensated for simply by adjusting the screw on the end of the block. This allows up to 1.5" total adjustment on each block. The adjuster slides forward and backward within a channel precisely milled into the solid billet aluminum block. Precision adjustments as minimal as .010" can be made. Also great for centering the tires in the wheel well! The pin diameter is 9/16" and can be provided in 5/8" diameter as well. 

These precision-made cast iron blocks vary in size from 1.5" to 5.5" for nearly every application imaginable. 9/16" steel centering pins keep the axle accurately aligned, while the built in taper retains the correct pinion angle while the suspension is raised upwards. The specific configuration of the block itself allows the user to mill the overall height and taper amount to whatever custom dimensions that are desired for a particular application.

These strong aluminum shim blocks are intended for fine tuning the pinion angle. Precise pinion angle results in proper u-joint angles, which ultimately eliminates driveline vibrations and unnecessary u-joint failures. These shims can either be used to tilt the pinion angle upwards, or downwards, depending on the needs of an individual application.