for 33's i would bother doing an gears.
If the rear end goes out, get a tru trac and 3.73's.
I have 3.73s and 33's and it works great, got plenty of pull for a little 4.8
you shouldnt be bad with your stock gearing. 4.10's would help city but hurt you highway. but 3.73's arent worth the amount that it costs to regear.
geoff drove around for like 5 years with that gearing and 35's
i would run what you have, and if you feel the truck has no balls then worry about changing them.
NOTE realize no matter what you do, your gas mileage is going to go down in some way because you will have a heavier tire on the truck. and it takes more to make that bitch turn.
Especially since you're a 6-speed. I'd think 33s with that gearing wouldn't be too bad.
Its an 08 with the 6.2, those always got the 6 speed IIRC. I had 4.10s with 285s and it was awesome but they were stock, for 33s I wouldn't bother with gears unless you had 3.08s or something similar.
tyler just so you knoe 285's are 33's