Unless you go wider on the wheels I'd not go 305s. We got a whole 8k miles on a set of BFG A/T 305s (they are E rated but w/ a max of 65psi). The tires delaminated (tread separated from tire carcass) -- we had them on stock wheels tho. Now we have 285/65/18E BFG A/Ts and they will be the last set of BFGs I run. I loved them years ago but these things took a ton of weight to balance and also we run them right at their max capacity and they look too flat to me. Empty I drop pressure as you and others have said and I get this strange vibration about 65 mph, that the tire shop can't balance out. We run Rancho 9000s on all corners and adjust them for load too...

I'm going back to stock size and Michelins which have always been a quality tire (they own BFG, so you'd think BFG would have better quality, but not in my opinion).

Our situation may be different than a lot of folks since we have a slide-in camper and run a 1.5' hitch extension and about 750lbs tongue weigth with loaded trailer. We are right at the rated capacity of the rear axle of 7k lbs

 

I have been running the Michelin E rated OEM 265 size and just LOVE them...
BUT--- I wish they made them in the 285's.....

Oh well

 

How wide you can go on tires is more a function of the 7.5" wide stock wheels than overall height. I wouldn't go over +4"wide, meaning 285mm or 11.5" wide tires on that wheel, but other people will tell you that running up to +5" (305-325mm or 12.5") is acceptable. I think anything over 4" wider than the rim is too much. The taller the tire, the wider you can run because you have more sidewall to flex to keep the tread block from deforming, so a 35x12 would be comparatively better than a 33x12 on a 7.5" rim.

Lift height wise, my largest reference point on stock wheels is that 34x11.50 (295/70/18s actual measurement) clears fine. 35x12.50 on non-stock wheels rubbed under a 2" leveling kit, but they were backspaced out further. If you can find a 35" tall tire that's 12" wide or less you could probably fit it in, but 34.50x11.50 is probably a reasonable maximum height and width to stay on a stock wheel at stock height. You probably won't find that exact size, so 285/75/17 is the largest I'd go on stock 7.5" rims at stock height.

Rough conversions:
265/70/17 - 31.50X11
285/70/17 - 33x11.50
285/75/17 - 34x11.50
295/70/17 - 33.5x12.00
305/70/17 - 34x12.50

 

Been saving up to finally purchase the tires, will take your advice and get the 285/70/17, was wondering if there will be an issue if I have to run my spare which will still be the stock size of 265. Also how much performance and fuel mileage will I lose?

 

Do a google search for tire diameters. Will tell you what the diameter is for various tire sizes. For instance the 235/85/16 is almost identical to the 265/75/16.