4.29/4.30 gears are an oddball size. you just need to make sure the fronts and rear match. They would be a good choice for "more" gearing for 33's or "less" gearing for 35's

I'm running 4.11s in mine with the Windsor and have never had a issue even when I was running the original 3 speed. The low end power is more than enough on mine and isn't nearly as built as yours. With the zf it is almost overkill in 4 low. I would vote though for 456 since it seems like highway isn't often.

Selectable would be my vote. Locked on the street can be a pain. Do they make electric for the 9 inch now?

There's a significant change going on in the off-road design school now, where many places recommend putting the $$ in the front locker vs. the rear if you're only going to do one. Think about it, the front end does much more "pulling" being under the weight of the engine vs. the back "pushing" you up and over obstacles. I know that, given the same locker setup front/rear, I would rather have to get "out" of a bad place on just the front end vs. just the back end.

My '83 BBB was set up with 4.88s and a ZF with 35" tires and an Ected up front/spool back. I really like the way it's a HD LS when not turned on, I often forget to turn it on because I've already climbed the obstacle.

I recommend keeping the same type of locker front/back ie ARB or Ected. The Ected would mean you'd have to go with an 8.8, but that might not be a bad deal in the long run.
Joe

On a mostly stock rig that has weaker front axle components than rear I would put the locker in the back.

I'm saying the stock 28 spline 9" axles are more durable than the stock 260x front shaft u-joints.

I must have read some of the same material as Joe, my 1st locker when into the front of my Bronco based on the whole "it's up in the air and has less traction" idea. I was never disappointed with that decision. When I added my rear locker it was as if I was cheating the traction gods. I don't wheel much with brute force, but when I make stupid decisions (mud, FWD only, etc) the part that breaks on my truck is the front shaft u-joints ears. I've gone through 3, both long and short side. I haven't broke a rear 28 or 31 spline yet. This is my personal experience only, I haven't done a ton of wheeling, but I do try to get out as much as possible.

Have 351c, np435, and 35s, was hoping for the best set up to drive to the trails as comfortably as possible. Bronco is also my daily driver so thought 4.29 would be a good highway choice. Interested in this ected locker, never heard of it

4.29 is a good option, if a bit odd. I ran 4.11s with a 302, np435 and 35s and was pretty happy with it. Good highway gears and worked well for what I was doing offroad.

My fear with choosing a less common set of gears is you are running trails in Moab for a week and knock off some teeth on a ring the second day. The chances of you getting another gear set in time to salvage the trip are dismal. But chances are good, you'd find 4.10's, 4.56's etc.

That is very true, maybe I'll skip being exotic and do 4.56. Justin sorry I didn't make it to help the other weekend. Sick baby

JM's advice is good. No worries, we had many hands. Hope your kiddo is feeling better.

ARBs are the way to go.

I have been running them for 12 years and 130,000 miles now. Dispite fears about air lines and o-ring seals failing, it just doen't happen often. The lines are very robust and it is CHEAP to carry a spare line and fittings. Think about it for a minute, people don't run cable actuated brakes because they are a afraid of a broken hydraulic line. Yes it happens, but with proper maintenence, you minimize your risk.

I have only cracked one ARB line. It happened at a time there was so much ice packed up under the truck, the suspension couldn't even move. A chuck of ice fatiqued the line right at the rear diff and it developed small leak, but the locker still worked!

I had a detroit in the rear of my old rig, which was a super cab Ranger (128" wheelbase) The Detroit worked all the time, but you could feel it trying to push the truck right or left depending on which side engaged first. It also wore the rear tires at about twice the rate of the fronts. The ARB is very predicated on the trail and much better for heavy throttle hill climbs. With the Detroit, the tire that is acutally pulling on a hill climb would lose traction and the power transition to the other tire was clunkly and would cause momentary stalls in forward progress. This simply does not happen with a spool or ARB.


As for gears, I would stay away from odd-ball ratios like 4.29s for the same reasons already stated. 4.10s and 4.56s are extremely common. For 35s without OD, I would definitely go with 4.10s. This is how I'm rolling around right now and I would not want to run more RPM going down the highway. I'm in the process of installing a ZF-5 to gain overdrive, and when I switch axles, I'll be going with 4.56s to match the new transmission. (This is the same tire size/gear combo I have run for 12 years on my old rig.)

Thanks to Digger & RJLougee for the insight into how different lockers affect hardcore rock crawlers. I've never done the stuff you guys build trucks for. I have never felt like my locker was making the truck track to the side or missed a 'line' because the locker moved the truck off line. Interesting stuff & food for thought.