Have it magnaflux for cracks first and then decide. The crankshaft company should be able to guesstimate how much turning down it will take to fixed that throw versus welding it and the mains , they usually warp when you weld a throw and then the crank has to be straightened and turn the mains to get them concentric with the center of the crank again Any chance of having the one throw turned downed and hard chromed that fixes the bad throw and usually the crank doesn't need any work on the mains Look around, it is expensive, most people have all four rod throw journals done at the same time :think, you can bring it(the size) back to stock also :