If you don't have some already, 3.5" BS wheels. All front steering components should be upgraded if not already. You should get familiar with ball joint options if not already. May or may not need to trim more pinch seam in the rear, and depending on where your rear axle currently sits, might want to push that further back just a bit more since you have adjustable rears. That could cause interference with rear sway bar, and moving that back will probably cause interference with your muffler.

Regearing will be the biggest thing. 4.10s will get old with 37s. Since you have a rubicon TC, you should really look at 4.88s. I have 5.13s in my non-rubi 3.6L, and it's a bit aggressive for most. Cruising 3000 rpm on the interstate is not ideal. Mine is not a DD, so I deal with it for the offroad aspect of the gearing. I've been on 37s for 3 years, and I wheel pretty decent. IMO, Rubi 44s are a ticking time bomb with 40s.

 

Brakes need to be upgraded, especially since it's the DD. With wanting to do 40's and thinking you'll still daily it, you should be looking at one of the brake kits that increase rotor diameter or better yet, add more pistons to the caliper. Safety first.

 

$10,000 you are willing to throw away for the 37's, double that for the 40's. don't worry about a big brake kits, the new heavy duty WIDER axle should come with big brakes.

 

 

From someone who built up Rubi 44 front axle, I'd say this......if you're doing the work yourself, it can make sense. If you're paying someone to weld all that on, then regear et al, it starts to make less sense. If you're adding more HP, you might want to consider Dirtman's suggestion of going to larger full width axles that are going to support that a bit better in handling the power and bring it to a stop with more significant brakes.

If you do decide to add truss and gussets to the axle, you may as well chop off the LCA and shock brackets and add new 1/4" brackets for those.....and the problem you will run in to (as I did) is that with the lower gussets installed, you can't outboard your shock mount enough cuz the gusset gets in the way. Maybe that wouldn't be as big of an issue if you felt the RSE inner gussets were enough, but all of the outer type gussets will eat up space on the axle tube. I have the artec truss, gussets, TB, LCA, and shock brackets (outboarded even more with modified Metalcloak relocates). I know a few people with the Evo truss etc and are happy.

You'll also need new rear axle shafts as the factory flanges gonna bend fast with 37s or larger, and if you thing you're going to ever be crawlin round on rocks and using your lockers, I wouldn't be surprised if the Rubi locker starts giving you issues. You really may want to put some serious thought in to some full width axles before setting down this path. I've run a build like you're thinking for several years now, but the biggest difference is I'm putzing around on ole 285HP engine.

 

What's up... I've been running 38s for about a year now on my 07 4 door Rubicon. Yes, I have a Dana 44 on the front axle plans are to atleast have C gussets and sleeves put on soon. I have regeared from 4.10s to 5.38's, Adjustable control arms, HD Terra flex Tie Rod and Drag link, Flashpaq super chip, and HD Ball joints, and Fox ATS Stabilizer. It's not my DD and I don't do any major wheeling. I agree with the other post about regarding. It was a MAJOR upgrade as now I can do 60mph at 2k RPM where as before I was AROUND 27-3k RPM at the same speed. That's pretty much all I've done so far so good. Oh and G2 gears have worked fine for me no problems! Hope this helps

 

I think there is more to this comment than meets the eye, cuz RPMs don't drop when you regear lower, they go up (assuming tire size stays constant). I'm confused as you've been running 38s for a year, but the regear was fairly recent (in June you had 1k miles on the gears).

 

Sleeves are useless. Skip and just truss and gusset.

 

Decide now if you want 37s or 40s, and build for it. Don't throw away money upgrading the Dana 44s for 37s, and then decide you want 40s later. I just went through this same decision on my 2017. Decided on 1-tons and 40s and love it. I do DD mine, but I spent the money in all the right places so it still drive, stops, and handles well. At 80mph with 40s and 5.13s, I'm turning exactly 3000rpm.