3.73 vs. 4.10

I have a 2003 5.3 silverado with 3.42 gears. I want to put in either 3.73 or 4.10 gears. Does anyone have experience as to which one is better? Is their a big difference in gas mileage between both of them. thanks

Better for what, acceleration, economy, towing?

I have a 2003 5.3 silverado with 3.42 gears. I want to put in either 3.73 or 4.10 gears. Does anyone have experience as to which one is better? Is their a big difference in gas mileage between both of them. thanks

Rule of the thumb the lower the rear end the lower the gas mileage.
Why do you want to change to a lower rear end?
Also tire size plays a big part in to.
Here is a link that may help.
http://www.differentials.com/install.html

MT

My 02 Xcab Z71 had 4.10 and my 05 CC Z71 has 3.73. In hilly western PA, I like the 4.10 better. Gas milage is damn near the same runing around here. With 4.10's, the tranny stayed in 4th gear more and the engine didn't have to work as hard pulling hills. In flat lands, you will see the 4.10's getteing worse milage than the 3.73's and 3.42's. Terrain, tire size and use will determine what is best for you.

I want the gears for acceleration. The tires and rims are stock from chevy. Their the 17"s. Is their a major difference in the gas mileage between the 3.73 and 4.10. I live in south texas, so the highways are mostly flat with a couple of hills.

4.10 would be a waste w/ only a 5.3 imo the 3.73 would be a better choice

The reason I wanted to know which gears were better is because a friend has a 2002 silverado with 4.10 gears, a hypertech programmer, and a K&N CAI. This truck does 15.3's in the 1/4 mile. Anyways i'm leaning more towards the 3.73's now. thanks

Rather than change the rear end you might consider a lower diameter set of tires which would give you the same affect.
And a lot easier to change back if it does not work out.
And remember your freind has a hypertech programmer.
If you get one geared down for a good 1/4 mile run it may affect your top end or regular highway driving and gas mileage.
Good Luck
MT

The reason I wanted to know which gears were better is because a friend has a 2002 silverado with 4.10 gears, a hypertech programmer, and a K&N CAI. This truck does 15.3's in the 1/4 mile. Anyways i'm leaning more towards the 3.73's now. thanks

Is this your main goal? My buddy Eric went 14.9 with a 5.3L, stock gears, stock tune, aftermarket intake tube with no filter, and a set of 26" et streets. He would have went a little faster, but his truck was cutting off before the 1/4. Does your buddies truck have a 4.8L in it?

My buddies truck is a 5.3 with only a K&N intake, a hypertech programmer and the 4.10 gears. His tires are stock and everything else. I would change to smaller tires but I do not look that look. I like the stock look of tires.

My buddies truck is a 5.3 with only a K&N intake, a hypertech programmer and the 4.10 gears. His tires are stock and everything else. I would change to smaller tires but I do not look that look. I like the stock look of tires.

Single cab or extended cab? My truck ran a 15.4 with the old 4.8L, superchips tuner, airaid intake, and borla exhaust. This was with stock gears and a stock g80 posi and low profile tires. His gears aren't really helping him out that much.

His truck is regular cab fleetside. Mine is a 2003 5.3 with volant CAI with ram air scoop, hypertech programmer, and a borla exhaust. Everything else is stock. The gears are 3.42. Its a regular cab. Do you know as to what it might make in the 1/4 mile.

His truck is regular cab fleetside. Mine is a 2003 5.3 with volant CAI with ram air scoop, hypertech programmer, and a borla exhaust. Everything else is stock. The gears are 3.42. Its a regular cab. Do you know as to what it might make in the 1/4 mile.

Your truck should easily run mid/low 15s with those mods. It's amazing how much these trucks vary speed wise(take Eric's truck for instance.....freak truck). On average though, with those mods, you should be able to run the same times as your friend. Is he hooking up pretty good when he is getting those times, or is he spinning somewhat? How do you do against him when you guys line up?

I still have not raced him yet. I have not seen him at the track, but i'm guessing his truck has to do spinning. I forgot to mention that his truck also has an exhaust. Not sure though, its pretty loud probably flowmaster. I just have the hypertech for the mean while, till I get enough money for the nelson tune!!

If your not pulling a trailer or wanting to get off the line fast go with the 3.73. 4.10 sucks down the gas, but is great for pulling a heavier load.

I've very happy with my 3.73s. They give me plenty of take off out of the hole, and still give me alittle topend to play with on the highway. :evillol: