I have an '07 Wrangler Unlimited with stock 18" rims. The stock tires are 255 70R 18s, mounted on 18" rims that measure 7.5" in width. I wanted to get wider tires, so how wide can I go with the stock rims - 275, 285? Also, I wanted to get wheel spacers (1" - 1.5"). Do you need any special modifications to prevent damage to wheel bearings or axles? Please let me know. Thanks.