i have a 93 grand cherokee lookin gfor a good on and off road lift 3 or 4 in lift i want the arms, springs, shocks, sway bar links preff quick discos, and tcase drop if need for vibration, and brake lines if needed. was looking at the rough country 4 in and the rubicon xpress 3.5 the xpress was a little much casue i found bumpers i want as well so looking for a good highway and street as well if i wanna go play a good one there to so and suggestions?

Rubicon Express has a good reputation, as does OME lift kits.

I would strongly advise against a transfer case lowering kit. Although it's a cheap solution to possible driveline vibration, it is inefficient and can cause some problems of its own. First, by lowering the t-case, you're losing some of the ground clearance that you're trying to achieve with tall tires and a lift. Second, any decrease in driveline angle that you gain in the rear driveshaft is at the expense of increased driveline angle in the front driveshaft. Third, you cause a permanent tilt in the engine-transmission-transfer case setup, and this can adversely impact oiling characteristics. Many people have lowered the t-case without adverse impact, but I've known some that had bad things happen. Why take a chance?

If you're going to spend all that money on an expensive lift, and new tires (and possibly new wheels), why not spend just a little more and fix the vibration problem properly with a double-cardan (CV) joint at the front of the rear drive shaft. If you do, remember to rotate the rear pig so it points at the rear output of the t-case.

whats the biggest lift you can go without lowering you t case the only thing holding me back from the t case drop was the ground clearence and how much does the cv thing cost/ and i already have 31's and im getting a stell on rims so im doin that but what do you think is the hightest i can go without doing a t case drop and possably preventing the drivline vib

I don't have a ZJ but a Wrangler. I went 6" and didn't need the Xcase drop kit. Did need the CV shaft and Yoke. I can't seem to remember the cost but it was around $500, small bump in the way of completion. To be sure I will have to search many of reciepts.
As for the Rough Country kits, you might check to see if there is a long arm kit. As for the springs they are stout and a good ride on the street.(not soft at all and not so stiff that you are bouncing all over the place.)
If I were just focusing on lift I would try the Rubi lifts you might be a little better off with results. I went with RC because I did a whole bunch of stuff all at once and did not have the extra grand to spare.

To some extent, each vehicle is different. Even within the same models, I have known some guys to install a 3-1/2" lift and not get any driveline vibration, and another guy do the same thing and get the vibrations.

I would advise installing the lift and the tires that are intended, and then drive the thing on the street. You'll notice the vibration more on the street than off-road. If you don't have the vibation, then you lucked out. If you do, then you have to address it. Some guys, as noted adress it by lowering the t-case. I think that's the wrong approach, and I'd advise installing a CV joint.

When I wqent from a 2" lift to a 4" lift I got vibraations. I didn't get an entire new shaft on my CJ7 -- I took the Jeep into the driveline shop, they removed the driveshaft, cut off the old forward yoke, inatalled the CV joint, balanced the driveshaft, and re-installed in on the Jeep. All that for about $200. Now, that was in about 1998, so prices are likely to be higher now, with labor costs really rising.

Keep in mind that some Jeeps will require a SYE before installing a CV joint on the rear driveshaft. On the other hand, installing a SYE on some Jeeps will lengthen the driveshaft enough to significantly reduce the vibrations.

As I said, do the initial steps and then see what you've got.