It worked. This is definitely a good tool. This makes my decision about wheels/tires much easier. I'm going to need a gear change if I get 20s, or my truck is going to be a . With OEM 20s, a set of 3.43 would retain nearly the same settings as I have now. I might go up to a 3.73, but I think 4.10 would kill gas mileage too much for me. 64 mile commute + 4.10 = broke

 

with them tires i would go at least 3.73... if you do 3.42 you will be disappointed.... with that big tire

3.73 = 1900 at 70 mph
3.90 = 2000 at 71 mph
4.10 = 2100 at 70 mph

i think i would maybe look for that 3.90....

several manufacturers make a 3.90 for your truck....

but i cant find a 3.90 for my 14 bolt 9.5"... if someone knows who makes a 3.90 let me know..

 

You'll be happy with the 3.73's...

Question.. are you still one-wheel-squeelin' too? b/c if you're going to change the rear, take a look at changing the G80.... just a thought.

 

This link makes the G80 sound good:

http://www.gmtruckclub.com/forum/sho...inner!&p=59612

I know NOTHING about this. Can you elaborate? What is better, in your opinion?

 

Search G80 on here and you will find that many on the board are not big fans of it. But if you plan to go with more hp down the road, like a cam, bolt ons, nitrous, or FI, save yourself the pain of getting the rear done twice (and twice the cost) and have them put a TrueTrac in there to replace the G80 when you get the gears done.

To see if you have a G80, you would see "G80" on the same sticker you found your gears on.

 

Mine is definitely a G80. I checked. Thanks for the info.

 

I'm in the same boat as you.. 5.3 with the 3.23s and I'm currently running the oem 20s. I am debating on going to a 3.73 or 3.90 but can't make my mind up.

And yes, my truck was a with the 3.23s/20s until I got a tune, and it woke it up nicely, but would still like a lil more pep off the line.