Smokeshow: The pattern was nice and even across the tooth on both sides and centered. (sorry I didn't take any pics of what it loooked like, because we were kinda rushing at that stage to get them in). The AAM gears looks almost like they have been pre-run and then coated because you can see a pattern on them, and the marks on the gear paint looked just like that, so we were happy.
Supercharged680: I ran the truck this evening, made several runs and it ran a solid 2 tenths quicker without the Nitrous than it did two weeks ago with the same ECM tune, so I'm happy. I did take a few pics with my phone of the front diff disassembled, and will try to post them when I download them.
At the track this evening, I discovered that the truck can actually spin off the line now without the N20, and my best N/A 60' is now 1.95,even with the front end gliding around a bit from the loss of traction off the line. However, it spins violently now on the N2O, so much so that it hops and slides around to the point where I'm afraid it will break something. I could only run a 7.893@88.10mph w/ a 1.81 60', with a 25hp smaller shot than I used for the one in my sig, but I wouldn't dare put the bigger jets in it. This SOB is brutal in first and pulls hard all through the gears. I think it can run a low 7.7 or maybe a 7.6 if I can get it to hook, so I'm going to order a progressive controller to calm the hit down a bit.
All in all, I'm happy with the gear change. It took a bit of time and money, but it wasn't that difficult to do, and was worth it, in my view.

 

I whole heartedly thought you would enjoy it under WOT and regardless it sounds as if your just plain happier overall, but how does it go through the gears at light throttle just cruising around? As far as the slip sliding wallowing around action, you may have to try and add some suspension limiters in the front to keep some weight on the front tires, it helped mine somewhat and while no it won’t stop the wheel spin, it did help in the wallowing around these things do. It’s just a shame that the 8.25” front differentials aren’t strong enough in the eyes of the manufacturers to build a locking front carrier, such as an e-locker or whatever to apply an even load to both front axles, instead of one side grabbing and then the other.

 

It is happier all around, even though as you guessed, driving off from a stop with very light throttle, it shifts early into 2nd, but that's no problem because the 4.10s help there too. The truck just feels more nimble and the best part is that it isn't revving (stalling)as on the convertor much moving off due to increase in axle ratio.
Thanks for the tip on the front end limiters. I just went through that with my race car that wanted to stand up on the bumper when I launched it, after -guess what - a new rear gear install!
The dumbest thing is that I have two Firestone Load Lift Air-Springs in the rear that I use for towing, but didn't have the sense to put any air in them last night. I'm convinced that would've helped keep some weight on the front, because everyone says this thing squats on the rear bumper when I launch it on the spray!
You are right on the front end. It spins the left front tire first and that causes the nose to go left, then a split second later the rear tires hook from the weight transfer and it launches forward and then I have to wheel the SOB to get it to go down the track and it just hops and claws its way all through first and then will bust the tires loose on the 1-2 shift (maybe I need to put some TM back in it). Pretty exciting for a 5700lb truck (with my heavyass in it), I have to say. But I'm more excited by what that timeslip says, so I'll try to solve this problem and see what I can get it to do. Thanks again.

 

Hell yeah man, glad to see your happy with the results. I am having Yukon 4.11s installed along with a TruTrac on the 23rd!

 

Honestly, if I had a stock motor that shifted at like 5600rpm @WOT, I would've thought twice about going to the 4.10s, because 1st would be pretty short, but my truck shifts 1st-2nd at 68-6900RPM, so it still does nearly 40mph before it shifts out of first.

 

Well said, my truck WOT shifted 1-2 right around 35 mph stock with 3.42s.