The factory powdered metal crankshaft gear has proven to be a weak link, failure of this gear results in severe damage to the valvetrain and cylinder heads. Protect your investment with this Heat Treated Billet steel gear from MMR. Direct replacement. As used by NMRA Coyote Modified and NMRA renegade record holders and the World Record Holder and first 5.0 Coyote in the 5's! LIFETIME WARRANTY TO ORIGINAL OWNER AGAINST BREAKAGE!!