I have an Ofna LX Pro basher and the clutch bell has worn out and no longer connects with the spur gear. Do I only have to replace the clutch bell, or is it a good idea to replace the spur gear at the same time? I saw a titanium(?) clutch bell on Ebay--is it worth the extra $ to get one of these instead of the stock ones, i.e. will it last much longer?

Also the stock clutch bell was 14T, if I replace it with a 13T would I notice much difference in low/top end?