A combined effort by Callies CNC programming and engineering staffs has resulted in a component that is distinctive and highly functional. Unique counterweight and rod arm contours produce a lightweight, aero-efficient crankshaft. Callies Series II Mangnum Mass Correct counterweights have been placed specifically to reduce bearing loads. By concentrating mass at the point of imbalance, the transfer of rotating and reciprocating assembly weight loads to non-adjacent main journals is limited. Ligher overall weight is an added benefit of Mass Correct counter weighting, resulting in improved throttle response. After years of service, Magnum crankshafts by Callies have established themselves as one of the most durable competition crankshafts ever produced. Magnum crankshafts are manufactured from ultra pure AISI 4340 steel. Callies then subjects this material to multiple heat treatments including our proven Ultra-Case nitride process. This heat treatment method produces a deep case that enhances strength while creating an extremely hard load bearing wear surface. The Ultra-Case process generates a layer of hardened steel deep enough to maintain its integrity even after a -. 010 regrind. All Magnum cranks will have gun drilled mains and fully profiled counterweights, regardless of engine type. a typical 4. 000 inch stroke Small Block Chevy will weigh less than 48 pounds. Magnum crankshafts are available for a variety of engine types and can be manufactured to your specific configuration.Pit Stop USA offers Callies Magnum Crankshaft - SB Chevy - 3.875" Stroke - 2.100" Pin - 400 Main 2.648" SAM21A-MG at low everyday prices. Be sure to check out all of our products from Callies Performance Products including Callies Performance Products Forged Crankshafts - Small Block Chevy.