Crower Big Block Chevy Lightweight Crankshafts are ideal for 50-pound race class restrictions, these 4340 steel crankshafts weigh 48 to 51 pounds depending on stroke, rod, and main size. They includes standard features like straight shot oiling, 1/8" radii, heat treat, plus lightweight profiling, center counterweight removal, four lightening holes and radius edges. The smaller outer diameter reduces rotating mass for quicker response, and less drag.