assuming its not bent or cracked just about anything can be saved as said before. easy way to check for cracks for free (not fullproof and should also be verified by a machine shop) but if there are large cracks you should be able to "hear" them. Take an open ended wrench or small piece of metal and just tap on the counter balance weights up and down one at a time. The crank should sound like a tuning fork if all is well. If it doesn't have a nice consistent frequency up and down then you likely have a crack somewhere. If it passes this test then you can continue with the rest of the process of cleaning up. A friend of mine who builds engines for a living does this when people bring in their "good" cranks, taps it a few times up and down before even starting, if it has a crack he usually finds it in seconds, if it all checks out then he pulls out the real equipment to start checking everything
