Manley 4340 "Pro Series"
These Manley Pro Series crankshafts can make your short block bulletproof. They feature forged 4340 construction and undergo a multi-step heat-treatment process and are then nitrided for added strength. The crankshafts are stress-relieved, shot-peened, and magnafluxed. The Manley Pro Series crankshafts have micro-polished large .125 in. radius journals, gun-drilled mains, and lightened rod journals for weight reduction. The counterweights are fully profiled and they are designed for internal balancing. Many require Narrowed Bearings.