I recently decided to get 4.10 gears to replace my stock 3.42 gears. I would like to know from the people who have done the swap if they have had a fairly large increase in acceleration from 0-60MPH? I don't do highway driving much and I don't visit the strip (and participate at least). I'm not too much concerned about 1/4 mile times, just want something to throw me back in the seat and keep pulling from a dead stop. I am going to have my local Chevy shop do the swap so I can get a 1 year parts/labor warranty from them. Check my Sig for my truck specs.
P.S. I know there was a similar topic not to long ago, but I didn't get enough info from that thread, so I'm starting another one.
Thanks,
Philip S.

 

how do you have stock 3.23 gears?? they never put 3.23's in? (until 2005 models, 3.23 is standard on 2wd WTF???). Anways, yes, 4.10's should be a welcome improvement. You should definitely feel the difference.

 

I mean 3.42, my fault. I know I need to have my speedo calibrated for the gears also, however I've also heard of the transmissin shift points needing to be changed, is this true?
Philip S.

 

You will need some kind of programmer to do this.
I have the HPP3. It works well and you can always take it off thet truck when you go sell it.

Just get a programmer.

 

Wait, the dealership can re-flash my PCM though correct?
Philip S.

 

get 4.56 and see that baby really pull.

 

No, I think that's pushing my luck as far as rearend breakage (especially the way I'd drive with 4.56s ) I called the local GMC/Chevy dealership and they gave a bunch of BS on parts and installation, prices such as $950 for ring and pinion only (Yeah, the guy had no clue, he said there was no such thing as 4.10s and I know stock 1500 Z-71s have 3.73 stock and optional 4.10s, and I can buy OEM 4.10s for $130 at drivetrain superstores). Then I called my local trans. shop, and finally people who are smart and know what I want to do. Anyway, I can get my PCM re-flashed at the dealership for $60. I think I can also add custom specs on the PCM during the re-flash for extra mula. Heck, 4.10 rearend gears, and a semi-custom PCM by the dealership to my specs, ahhh, acceleration here I come!
Philip S.

 

hey good luck with that and let us know how you like it, but if you went 4.56 you would be less likly to break things due to the fact that it takes less torque to turn the tires, youre getting so much torque multipcation through the gearset that its actually easier on things, youd be at driving speeds in no time, and highway would be out of the question probablly, imo. oh yea, you might want to search and find out what else you need to do but i think you will need to program abs also, im not sure on that

 

It is easier, but it's easier on the motor, trans, and driveshaft, not the axle parts. Like you said, it will increase my drive wheel torque. If I consider my driveshaft torque to be 260 ft. lbs., at my stock 3.42 ratio I have 889 ft. lbs. at the wheels, with a 4.10 I have 1,066 ft. lbs. And if for fun if I had a 4.56 I would have 1,140 ft. lbs. at the wheels. If I lay down 1,066 ft. lbs. at the wheels it's putting extra stress on on the axleshafts. I don't think breaking something will be a problem though, since my truck only weights around 3700 lbs. it's 2wd, short bed and I have a peg leg with 245 tires. I'll just be able to spin my tires a lot easier
I'll keep y'all updated.
Philip S.

 

I just had my rearend gears changed at a local differential shop. The cost was around $550 for parts and labor. I think I have a 90 day warranty. Two separate dealerships quoted me a price of $1800. That is a huge price difference! I saved enough by not going to the dealership that I was able to throw a little more into the rearend for an Eaton Posi and I'm still half of their price. The point I'm trying to make is that you may want to consider getting the work done in a local shop. The money you save may be enough to get you a custom tune from Nelson or a hand-held programmer.