The Eagle 442640006100 crankshaft is engineered as a replacement for GM LS9 engines that uniquely use a 9-bolt rear flange and a long snout for dry sump function. The 4-inch stroke is perfect for additional displacement to increase performance. The installed reluctor ring is the larger LS2-style that requires a more common LS2 crank sensor. Manufactured using ASME-certified 4340 non-twist steel that has been nitrided and QPAC micro-polished for a superior finish and wear resistance. Designed with a target bob weight of +/- 2 percent to reduce balancing time and often takes no extra heavy metal when combined with Eagle connecting rods and forged pistons.