Brace up the passenger side drop bracket some. Plate it or maybe get a tubular support to tie into the pivot bolt or something along those lines. I have yet to see a drop down bracket that didn't crack over time online and also from personal experiences with them. I've never seen one fail to the point of being a day ender but they definitely do crack, even in the crawler environments.
On the locker... I'm not remotely saying there's a right or wrong by anymeans and I've seen really good reasoning for going front only. My thing though... If you're say in the rocks on a flat trail lifting tires, imo as long as you still have a single drive tire pushing you're fine. So if it's a front or a rear, it's kind of a wash in that situation I feel. Now get in a scenario where you're on a solid rock, moab style, with a front locker and it either makes it hard to turn OR if there's sand on the hard surface it can make the front want to push or slide depending on situations. I had one where I was skirting a pretty deep hole that would've rolled me on my drivers side if I slid into it. With the front locker and the lean that the surface had me, every single time my front end would try to slide over into it cause of the locker. No other vehicle had this issue, only mine with the front locker. Next situation where lockers KICKASS!!! Up hill climbs... Your weight is naturally shifted over the rear of the truck. That's where most of your drive is coming from so I want both of those tires pushing 100% of the time.
Like I said though, there's a lot of really good arguments that I've seen for going with a front only. One of them being street driving manners which I can understand for sure. I will say though, I've got a detroit in the rear and I DD mine and only notice it maybe once or twice a month around town. I'm VERY impressed with the street manners of the Detroit over other cheaper lockers I've had in the past.
FYI, I've got the OG detroit in the rear 8.8 on mine and the Detroit EZ locker in the D35 up front. No issues to date with either. I've heard good about the Aussie though as well!
Not really intending to sway you either way on location of locker or brand... Just tossing out my 2 cents on what I've experienced. I would add a bit of support to at least that passenger frame rail drop bracket though! That one is advice from personal experience. Mine cracked in a few different places over time when I had them. I'd weld up the crack, plate it and then eventually find it cracked elsewhere. I basically chased cracks on it over the time I used it. LOL
