I got 285/70/17 Cooper STT's on my 04 z71 with the bars cranked. I've never had clearance issues in the front, but in the rear i had to cut out the plastic where its molded to accomodate the shock bolts. The tires contacted the inner fenders and kinda busted em up a bit when i first got em on. Only when i was really loaded or flexed out. Cutting the inner fenders is easy and harmless tho. Let me know if you'd like pics. Go online or to your tire shop find the mounted and inflated hieght/width if trail grapplers. Compare them to the STT (mine list at 32.8" tall brand new). I highly recommend the cooper stt's tho..Total bang for your buck! Only gripe is that they are a little noisy.