I now offer a reground cam with the specs of the early model (256) cam. It's the same deal as the Shell #1 cam I offer. It's $100 if you send me your cam, and I'll re-phase it for another $100. You will need to degree the cam before running it. The lobes are ground to preserve as much of the base circle as possible so the sprocket may need to be reset to time it correctly. Yes, that is more work, but I guarantee you will not get a cam that is so over-ground that there are no threads left on the adjusters for the lock nuts.
The 256 grind is a great street performer. Better punch than a 447 and better longevity than a Shell #1. Plus, you can run the stock valve springs.