Pro LS 6.0L Rotating Assembly

The Summit Racing™ Pro LS 6.0L Rotating Assembly is engineered for enthusiasts seeking enhanced engine performance and durability for their LS-based engines. This comprehensive kit includes a 4340 forged steel crankshaft, which is core hardened, tempered, and nitride hardened for superior strength and longevity. The crankshaft features lightning rod journals, gun-drilled mains, and profiled counterweights to improve engine acceleration, with maximum journal tolerances of +/- .0001 inches for consistent bearing clearance. Complementing the crankshaft are 4340 forged H-beam connecting rods, designed for an average piston speed of 5,000 ft./min. in street and drag applications. These rods are equipped with 7/16 ARP 2000 bolts, boasting 200,000 psi tensile strength, and feature dual ribbed caps for maximum structural integrity. The assembly is balanced to within +/- 1 gram per end and includes full-floating, precision-honed pistons made from ultra-modern 2618 forged aluminum alloy. The second ring is a martensitic ductile Napier-hook for strength and oil control. The assembly is specified for a 4.030 in. bore and 4.000 in. stroke, yielding an actual engine displacement of 6.7L/408 cid. It features a 1-piece rear main seal style and accommodates cathedral and rectangle heads with generous valve reliefs. Notes for installation and compatibility specify a 6-bolt flange and standard snout suitable for factory wet sump engines, with an exception for the 1999-00 thick flange LQ4. An optional thick tool steel pin upgrade is recommended for applications exceeding 1,000 horsepower with boost or 300+ with nitrous. The kit does not include a harmonic balancer, flexplate, or flywheel, and users are advised to reuse factory components or purchase specific replacements for blower balancers. Proper cleaning of oil galleries with mineral spirits and brake cleaner is also recommended.