I've got a YJ running Dana 60s front and rear with 5.38 gears. It's currently sitting on 42s, but I can get a pretty good deal on a set of 39s. I don't think it will make that big of a difference, but I'm wondering if anyone has went from one size to the other and if they had any opinions on either. The Jeep is a 95 running stock auto transmission and transfer case.

it really depends on what you use your rig for? we need more info on what type of wheeling you do. If you rock crawl primarily, 39s IMO will actually give you better turning and more maneuverability. but if your mudding, then no. give us more info and we can help you better.

It's mostly used for trails, creek beds and stuff like that. I avoid mud when I can, but I live in Ohio and wheel in Indiana and Kentucky, so it's not always easy to do. However, I don't do mud bogs and stuff like that.

Depending on the mfr for the tires, you'll be surprised of the little difference the overall height will be between 39s and 42s. Also, if one set is newer, bet the lugs are deeper than that with more wear, dah.

why do you want "smaller" tires? 42's worn out? Too big for jeep? Keep Breaking? Doesnt fit in garage? Why?

well, if your rock crawling, many of us out in northern ca actually prefer the 39s because of maneuverability on tight trails and rocks. Like the other guy said, are you breaking things with your 42s? The manufacturers of some 39s are almost really 40 inches and some 42s are only a little of 40 inches.

why do you want "smaller" tires? 42's worn out? Too big for jeep? Keep Breaking? Doesnt fit in garage? Why?
42s are IROKs, 39s are red label Krawlers.

It's mostly used for trails, creek beds and stuff like that. I avoid mud when I can, but I live in Ohio and wheel in Indiana and Kentucky, so it's not always easy to do. However, I don't do mud bogs and stuff like that.

42s are IROKs, 39s are red label Krawlers.

well, if your wheelin on "trails, creek beds and stuff like that" than I would keep the IROKs. I hate krawlers in the woods. MY opinion is that anyone who says Krawlers are good in the woods are only lieing to themselves to jusitify the purchase. IROKS kick butt in the woods, plain and simple.

Red label Krawlers are for rocks. Stickies break stuff easier and are now going to be well suited to your area and type of wheeling. Keep your current ones or get a new set of other tires in the size you want.

although red labels are the shit on rocks, they actually are sub par on just about anything else. Trails and creek beds, they are just going to clog and fill with dirt and mud, not to mention wearing super fast!!! If your not crawling rocks, dont get the krawlers, not just for the performance, but for the enormous price tag!!! IROCs are some on the best overall tires on the market IMO, good on the trails and creeks, rocks, and even ok in deep mud. STICK WITH THE IROCs, or if you need new tires, I've been hearing good things about the new Pit Bull tires, check them out.

I would try to go with a set of Pitbull Rockers if you can. The red labels are mainly for the rocks as stated above.

Thanks for the advice guys. I was just reading a bunch around here and most guys were creaming themselves over the red labels and I had a chance to get a set. I forgot that many of the people on here are out west. The IROKs are still in decent shape, although they've got some cuts. Any issues with them and I'm going to Pit Bull Rockers.

For overall trail use.I would stick with the Irocks.

I am in the ohio region as well. I went with a new set of 40" LTB's. I am not a mud guy, but to get to rocks around here, you will have to go through a little mud.
The irocks are better than the Krawlers for your use and the area we are in. The Krawlers loos good, but if not on rock, the looks dont get you far.
Haz-Mat 1

Haz-Mat. Where in Ohio are you? I'm down in the Dayton area.