I have an 87 4 Runner with a stock 4 cylinder 5 speed manual that I was planning on installing a 3" body lift and mounting 33/12.50/15 tires on. I recently heard that mounting 33" tires would greatly reduce power in my engine and make my fifth gear almost useless?? Would I be better off mounting 31" tires or do I need to upgrade my gears? Or will it not affect my engine performance at all? Any information on this would be greatly appreciated!

Mike