Any idea how to tell if I have a 2 or a 4 pinion rear end? how about how to tell if it is a 28 or 31 spline rear end.

Without taking the rear end apart?

1974 bronco, stock w v8

Also anyone done a lunchbox on a nine inch? I have done a couple on 8.8s and dana axles but never on a axle with a drop out 3rd. Just as easy? Does the 1810lr really work on both 28 and 31 spine 9ers?

Unless your axles were changed, they are 28 spline.

I put a Lock Rite in my 9", its a 31 spline out of a 79 Bronco. I've never done it before and it was real easy. It will work with 28 & 31 splines. I like it as much as my Detroit Locker, and I didn't expect to.

I don't know how to tell if its a 2 or 4 pinion set up. My 79 rear end had 2 short & one long pinion, it needed the longer shaft replaced with a hardened replacement part. I had to order one after I had everything apart and figured it out.

You may be able to get a good look at which pinion setup you have by pulling one axle and shining a REALLY strong flashlight down the axle tube. 2 pinion will have a single shaft across the side gears, 4 pinion adds small stub shafts that will butt up against the cross shaft. I also have a powertrax locker in mine and really like it.