i run V8 ZJ springs up front(about 2.25" of lift) with a 1.75" coil spacer in the rear and with 1.25" wheel spacers and 7" flares i fit 33's with no problem. i have an '06 LJ, so i don't have any issues with driveline vibes, but i've heard that some TJ's do at as little as 2" of lift. if you get vibes that would mean a t-case drop at least or ideally a SYE and new rear driveshaft.
hope that helps
'You may not realize it when it happens, but a kick in the teeth may be the best thing in the world for you.' - Walt Disney, Animator, Film Producer
'four wheel drive only allows you to get stuck in more inaccessible places' - George Noll