It isn't a good idea. If your clutch bell is metal, which is most likely is, then you'll have metal-to-metal contact and that can create interference that will mess up your radio signal. Also, the spur gear serves as a "weak point" in the transmission, because it's easier to replace a stripped spur gear than a stripped internal gear (whatever it may be). So I'd just get the exact same one you had. Make sure your meshing is correct. If you know the paper trick, use that. Works like a charm.