If you bang one out, absolutely DO make sure that both the bell and the shaft turn straight, and aren't dented when it's done. Dents in the bell will cause low spots that can grab the clutch at idle. Dents in the shaft will just make it harder to put the sprockets on. I'd say try using your old bell as a practice piece so you can get your new one banged out proper. If you buy one, same thing. Make sure it turns straight, and has no dents.