i have a 2000 ecsb sierra z71 with a 5.3, im sitting on 295's with a level kit. i'm looking to rebuild my rear end, i want to put in 4.10 gears (4.11?) and would like to swap to a locking rear in since i have posi trac now (im pretty sure). since i have never done this before and dont know alot my questions are whats a good brand for the gears and locker, and am i a complete idiot and getting above my head for wanting to do this myself. i'm active duty military and if you've been paying attention to the news i obviously am not raking in the cash. i want more torque for fun and light to light get up, i dont tow a lot or often and i do play off road, also on the list are cam/torque converter and tune btw, i appreciate any help fellas

 

i think i would go with a tru trac and 4.30 gears being you have over sized tires

 

how much differance would there be? i also drive this on the interstate a decent amount seeing as im 4 hrs from home and 2 hrs from my girl...

 

also is tru trac for the gears or the locker?

 

of my questions?

 

Trutrac is a locker. There are a lot of different brand lockers out here. I'm a fan of Eaton which is the Trutrac.

As for gearing, 4.30's would probably be good, mainly because of what the other poster stated. You are moving some pretty big tires compared to stock and they are also probably much heavier. However, a 4 hour ride on the highway may be using up some gas....What gears do you have now? 3.73? I don't think you will go wrong with 4.11 or 4.30 to be honest.

 

im pretty sure they are 3.73 now but not positive like i said i dont know a whole lot about rear ends, was there a higher ratio in these trucks?

 

Tru Trac is not a locker....... it's a Torque biasing limited slip. It doesn't "lock up" and it can't "lock up". Don't believe me....... okay, watch this:

DETROIT TRUETRAC DIFFERENTIALS - YouTube

Anyways it's a good limited slip if you like to road race..... which is what it was designed for.

Detroit locker hands down....... and yes I daily drive one in snow, ice, crappy roads etc and love it. If I didn't say anything to someone driving my truck all they would notice is the clunk it makes from the slack in the locker on initial takeoff...... that's it. A lot of what you read about them negative wise on the net is from forum junkies that have never even seen one in real life..... let alone actually driven something with one. Autot3k can give you another opinion on the whole locker debate as well...... he daily drives a 2010 2wd in winter ice and snow with a Detroit locker.

Gears.. I would go deeper honestly depending on the actual size of your tire. If they are 33 to 34 inches tall, go 4.56. 4.10's are a great gear for like on my trucks.. which have 245/75/16's lol.

 

Isn't this 4wd? What about considering the available ratios for the front diff as well. I also use Detroit Lockers on two different trucks. Completely satisfied with both. One has a very slight, hardly can feel "clunk" on take off, if in a turn. No noise just a feel. The other makes no noise or clunk feeling at all. Very satisfied with both.

 

Correct if I am wrong but you can get up to at least 5.13s in the 8.25" ifs. 4.30's are available for them as well just like the 10 bolt rear. Z71 in 00 would be a 4x4.... as the 2 wheel drive version didn't exist yet.