You don't need them if you don't mind either some wheel rubbing, or else adjusting your steering stops. Either way, you will lose a bit of turning radius if you don't use the spacers. On the other hand, the spacers are going to put a bit more stress on your bearings and will cost you money.Originally posted by Brent:
i want to run 31's x 10.5 on my stock YJ and someone sugested spacers but what are they and where do they go?
I ran 31x10.5 tires w/o spacers for a few years and didn't really notice the lost turning radius. You don't lose that much.