These Aeroflow Performance OEM GM LS rocker arms feature an upgraded trunnion and install easily on your LS cylinder heads without any modifications and a direct OEM(GM12681275) replacement rocker. The rocker is a pedestal mount, roller fulcrumstyle, and are made of ductileiron construction. Each rockeralso features an oil slot design to priority feed the roller needle bearings and keep them cool for long lasting durability and performance. All rocker arms are moly coated for wear resistance and smoother low friction operation. Each kit comes complete with 16 rocker arms and 16 OE hex bolts. Available in either straight or offset design to suit all GM LS series engines.