Callies BBB42B-MG - 4.375" Magnum Forged Crankshaft for Big Block Chevy Mk IV

Engine Big Block Chevy Material Forged 4340 Steel Rear Main Seal 2 Piece Balance Internal Stroke 4.375" Main Journal 2.750" Rod Journal 2.200" Balancer Bolt Thread Size 1/2-20 in Race smart with Magnum durable competition crankshafts from Callies. Manufactured from ultra-pure AISI 4340 steel, these cranks are subjected to multiple heat treatments, giving them unsurpassed wear and strength characteristics. With their gundrilled mains and fully profiled counterweights, you may choose from an available selection for a variety of engine types. You just can't beat the proven reliability and value of Callies Magnum crankshafts. • High purity premium 4340 forging • All rod journals are drilled with generously radiused lightening holes • Counterweights have been placed to reduce imbalance forces over the entire shaft • Each counterweight features Callies (Dual Arc) windage redcing edge • Perma Case Deep Nitride