Changing gears

[Stretch10]

So i have an 03 avalanche it now has 50000 klm on it always storad inside and undercoating every yeay truck is in new condition...i put a 3" lift on front and a 2" on rear went with the biggest tires i could fit
Has 373 gears and a 5.3 lt
Im thinking about putting 410 gears has any one done this

 

[Auto Parts Guy]

What size tires are you running? And what is your plan/goal with the truck?

 

[ygmn]

4:10 I think were an option for 2003 I know they were in 2002.

3.73 was kinda the popular standard ratio

IF you do this I suggest getting a more robust differrential (z71 came with locker) that can handle more torq because as it is the rear end is kinda on the weak side if you modify anything from radiator to rear tires.

 

[Maverick408]

I am also interested in this. My 2013 Avy is stock with a 3.42. I just put a BDS 4” Lift w/ 34” tires on her. Waiting for my diablosport in tune trinity to arrive to recalibrate but really think I will need a re-gear to wake her up. I do no tow at all and am looking at the 4.10 or 4.30 Nitro Gear front and rear set.

 

[Auto Parts Guy]

I re-geared my avalanche from 3.73 to 4.88 and no regrets. I also used the diablosport tune to correct the gears and speedometer. I would suggest going as deep (low, numerically high) as you consider.

 

[Maverick408]

I re-geared my avalanche from 3.73 to 4.88 and no regrets. I also used the diablosport tune to correct the gears and speedometer. I would suggest going as deep (low, numerically high) as you consider.

If I don’t tow, do you think I should go 4.30 or go lower to a 4.56? How is your top end with the 4.88?

 

[Auto Parts Guy]

If I don’t tow, do you think I should go 4.30 or go lower to a 4.56? How is your top end with the 4.88?

I would go 4.56 personally. There isnt that much difference between 4.30 and 4.56. Just depends on what your goal is in the end. Play around with a gear/rpm calculator to see what the difference would be with your set up and compare that to where you are now. Make sure you actually drive your truck at 55 or 70 to see the real RPMs and might want to use a GPS speedometer to make sure your current set up is accurate. Most tires arent true to their size exactly.

Keep in mind I have the 8.1L, but I cruise at 75mph at around 2800 RPMs in overdrive.