Been running 33's on mine with no problem. The AT/torque converter make up for what you don't have in gearing. I don't get into overdrive as often, of course, and the added weight and rolling resistance(especially if you are going wide) will hurt your fuel mileage.
2357515 stock @ 28 in tall
new tire "says" 33 in tall
stock gear 4.11
33 div 28 = 1.17 1.17 is the difference in tire size
1.17 x 4.11 = 4.80 is the gears you need to make the power band like stock.... this endith the leson
You can run 33's just fine with the 4.11 gears - I've been doing it in my daily driver for a year. You will find that the tranny downshifts to 3rd often going up hills at 50-60mph. If it becomes a problem you can regear later. I am getting a little tired of it and am considering going to 4.56 at the same time that I do ARB lockers, maybe some time next year.