4340 CRANK CHEVY BB INT 1 PC 4.250" STR Eagle forged 4340 steel center-counterweighted Cranks feature a non-twist forging, center counterweights for added stability at high RPM and high-power applications. 125" fillet radiuses for superior strength so chamfered / narrowed bearings required, nitrided surface and micropolished. Intended for the most demanding applications. .