Harmonic Balancer Bolt w/ Thick Washer, GM LS1/LS6 4.8L-7.0L, 12-Point , 27mm Wrenching, 180,000 PSI, M16 x 2.0 x 4.330" Under Head Length. Fits all versions of the GM LS engine - except the LS7/LS9/LSA.;180,000 PSI Rating; Made from High Strength 4135 Chrome Moly; Black Oxide Coating; 27mm Wrench Size; Extra-Tall 12-Point Bolt Head - Won't Strip or Allow Socket to Slip Off; Large Diameter Extra Thick Washer; Reusable - Not Torque-To-Yield;