Well, they only have abouy 3.5k on them so i dont know. Tread wear was the only concern i had with these tires. I had some 35s on a past jeep and i dont think they were going to make it to 40k. These look good so far. Personally, i like bfg km2 for a dd because of the wear, but they run very small in 37" (or should i say 36")

 

Im not quite sure I would go 37s on the D30 front axle. I was wanting to go 37s on my 2013 Rubi but opted out for 35s due to the added maintenence and strain on my rubi. Matt could tell you or maybe some of the other guys could tell you. Some guys run 37s on the D30 and on the D44 Rubi front axle. Check with some of these guys and do a little research to see if thats something you may want to get into. I went with 35s

 

This is a good point. Research. I sleeved and gusseted my 44 nefore i put on the 37s

 

If you put gussets on your d30 and don't install a locker it should be able to handle 37s... There is always some risk but you run basically the same risk running heavy 35s on a d30

 

In reality, when you look at the weights of 35 vs 37, not much difference. I have heard what he is saying begfore, a locker on a d30 creates a wek link at the shaft spline but i have no personal experience with it

 

It's not so much the weight that is the concern, its the increase in rotational mass due to size. The bigger the tire, the more torque and power it takes to turn it. D-30's have a tiny pinion gear which is the weak link. I personally wouldn't go over a 35 on a D-30 as it simply won't hold up if you plan on wheeling it very hard, and I definitely would waste the money putting a locker on one

 

It depends on the lift. I have a 4in lift and have no drive shaft issues at all.

As far as 37's weighing a little more than 35's, you must remember that its not the diference in curb weight that matters. Its the weight of rotational mass. Even with 35's you will want to beef up your axels but with 37's you absolutely should beef up your axels.
IT would also be problematic for the suit wearer climbing into a rig that high even it it had side steps. I have a 4in lift on 35's and people complain getting in and out of it. Just saying. There are softer things you should also consider.

 

Longer front LCA's will actually cause the front DS to fail. By extending the length of the lower arm to correct caster, you are also increasing the pinion angle of your front DS. Those stock rzeppa joints don't have a lot of allowance for angle and they will pinch the little rubber boot and tear it. Once this happens, you'll need a new drive shaft in a hurry. There's confusion about the boots on the drive shafts. The one that causes your drive shaft to fail isn't the big plastic accordion looking boot in the middle. That boot just covers the slip spine, and you can live with a missing or torn spline boot for a relatively long time. My front ones been torn for over a year and the back once been half missing for longer than that. Automatics will rip the front one on the transmission pan. I ripped my rear one on rocks. No big deal and I'll replace the shafts if and when they fail.

The boot you need to worry about is the one that covers the rzeppa joint where the shaft attaches to the transfer case. Rip that one and you need to figure out a plan quickly. I've been running over 4 inches of lift for a year and both of mine are still fine. The front one is at a bad angle, but hasn't failed yet.

Here's a vid of that FT kit you were considering running a triple black rated rock garden at Gulches. It's a FT 3" with 3/4" spacers, adj track bars, and Bilsteins. Watch the flex on the front after clearing the big ledge.

http://youtu.be/H_pw_v-86kc