The ARP 4age rod bolt kit is designed to be used with stock rods at slightly higher rpm. These bolts are made from 8740 Chromoly steel and heat-treated in-house to 200,000 psi tensile-strength rating. This kit comes complete with high-quality bolts and assembly lube. This rod bolt kit is designed to work on the 4age 16v and 20v engines with STOCK connecting rods!