I have a pair of Sonny Bryant 4.750 stroke cranks for sale. These are cut for dual keyway (blower snouts). The cranks are standard on the mains & rods. We have magnafluxed both of these and they have no cracks. They are for a Gen4 style two piece rear seals. If you are building a big cubic inch big block and planning on making a ton of horsepower, you will need a serious crankshaft.