The Chevy II Down Bar Shim Kit works with Detroit Speed's Chevy II Front Frame to align the frame during installation. The Down Bar shim kits will allow you to easily square the Detroit Speed Chevy II Front Frame. They replace the original stock shims that may be worn or missing. The kit includes 4 - 1/16" shims and 4 - 1/8" shims. The shims are electroplated to insure corrosion resistance.