What's the width of the stock 275/50/22 tires? Like 11", 11.5" maybe? Then compare it to 12" wide 305s, take half the difference between the two ( that added to each side of the stock tire) and see if you have that much room available on the inside if you were to go with the wider tire.
Basically turn your current wheels lock to lock and see if how much clearance you have on the inside near the upper control arms. This will give you a better idea if you have enough room. I can tell you with my setup I have no rubbing at all, but again I'm on 9.5" wide wheels with a +26 offset.
One thing to keep in mind, not all 305/45/22 are the same( some are wider than others, some run narrower than others), So be sure to check the specs on what ever tire you decide to run if you do change sizes.