Made from billet 4340 H.T., these are designed for those of you that are running higher spring pressures and larger cams these prevent the rocker shafts from breaking at their weakest point, the mounting holes. These are a good thing to have on any Buick V6 running the stock type rocker shafts. Because of the increased manufacturing cost of these there is only 4 pcs included in the kit to be used on the outer two bolts only..