I built a 421sbc from a world products motown block!!! 3.875 crank fell into place,NO GRINDING. EAGLE makes a good crank for 499.99,my cost, retail for 599.99 its a good piece, especially if street car, Ive raced it to 8000,all season NO PROBLEMS now I want to build a 472!!!!!!!!!!!!!!!!! Good luck try it its fun, get good advice fromm good people and have fun !!! David.