welding on main shaft?

So ive got some extra parts and 2 bolt on yoke a-body main shafts (i run a trunion style yet in my dart) that are in good shape except for some small rust pits on the bearing surface for the roller bearings that ride inside the input shaft. Anyone think welding them up & turning them down to original dia. In a lathe would be a bad idea? Hate to toss em for some rust pits when all else is great. Thanks for thoughts.