Alright guys, I have come across some more funds. So tires are in my near future. Should I go all the way with the 32s (265/75/16) or 31s (265/70)

I have been second guessing my tire sizes since I started this project. It all comes down to gearing and how the truck will perform on the trail. With 31s I will be sacrificing clearance for only slightly better engine braking and gearing than with 32s. But I need someone to tell me what they think.

HELP!

With the 2" bd lift you have now you more than likely could go up to 33's.  I have 245/75 =30.8 my only complant would tire rub on the frame.  If you have wheel spacers 265's should be ok.  The other thing to take into account here is grearing.  If you have an AT trans with 5.12 gears your done.  how ever if you have MT trans. you can go up to 5.12 which would be about right for 32's.  Now I have to say that with 245's that I have there has been some power loss but thing too bad I still drive 65+ and pass people.
George

I automatic. I have no worries with the clearance. I have already test fit and twisted it on a lift. I am just worried about the gearing. What I'd like to know is that 30.5" tire your running causing you any trouble on the trail, like step inclines or declines? I mean a full inch will not make much difference on the trail in ways of clearance but it does push it with the gearing I think. It is just that much farther away from stock. I am inclined to go with the 31s but I don't want to do myself another injustice by settling for a smaller tire when I would like to be in the 32s. Make any sense?

another thing to think about is bigger tires more stress on the front CVs.  But bigger tires will help in your ramp over angle.

Returning after sometime away (with another week coming).

My conclusions for tire size: what is planned in the  future (1yr & 3 yr) for t-case gearing, axle gearing, lockers, or basically drivetrain upgrades?

Breaking it down, you are pretty much stuck with the stock gearing for now due to the auto.
However, there is a possibility to throw in the GV axles and have taller ratios/lockers available. Gears is what makes the difference between a stock tired/stock ratio truck and a larger tire/geared truck. Compensation is absorbed in the auto to a point.....mostly in acceleration as well as speed passing. You will notice this greatly if the tire difference is large. Thus the change in axle ratio is necessary or someplace in the drivetrain after the main trans. (Think Sami case design, ratios in both hi and lo ranges.)

There is a guy on Pirate now taking a NP231 (mostly Jeep applications), cutting it up (all aluminum case), keeping the planetary gears, and sandwhiching it between the trans and another 231 (length is measily ~7"). The low range is 2.71:1 so you are getting double low. Now think, if the planetary ratio was 1.5-1.7, that would better for streetability and keeping R&Ps in stock or near stock size. This would compensate for the larger tired vehicle no problem. He's looking at a cost effective way of mimiking Klune. Klune took the planetary gears and added an external case, making the case adaptable to many trans/t-case combos as well as rotating the case for better belly clearance.

What I would suggest, there has to be a compromise on you. Don't go with the largest tire you can fit as you will have noticeable consequences in street performance. Don't go with a smaller than necessary tire as you will have consequences offroad. Weigh how you want the vehicle to perform 75-85 % of the time. Pick your size.

Don't forget to get an aggressive yet compliant tire. Who knows, by the time the 3rd year comes along, those tires will be worn down and will need replacement. Then you'll be debating about adding another trans or something and supercharger, intercooler, etc.  Gas prices by then will be $4/gal. You'll be wanting to get a diesel conversion for sure.......