I have a 2005 Chevy 1500 2wd 5.3 liter. Right now the ring and pinion is a 3.23. I am very close to like within the next week ordering gears and am torn between 3.73s and 4.10. What I want to know is what cruise rpm at 70 should I expect? I know that performancewise with my wheels (24 inch Bonspeeds) that the 4.10 would be best, but I am afraid that my gas mileage on the interstate would suffer too much. I am also afraid that going from 3.23 to a 3.73 would be enough to notice but not eneough to make me happy. So people with 4.10 and 3.73 with stock sized tires please help me and let me know what your cruise rpms at 75ish are. Thanks

 

Go with 4.10s
I don't know what size tires you have, but with 31" tires you're only gonna be at 2200rpm at 70mph.
with 24s you'll probably be at a bit lower rpm.

PS there is a gear calculator sticky in this section

 

i ve been looking into it myself and everywhere i turn i hear go up 2 sizes to notice the difference you want

 

With 3.73's ya won't need a new carrier- and yes, you will notice a difference, especially with a 2wd.........

 

3.23? My '05 came with 3.42's I think. I went to 3.73 and 30.5" diameter tires on 17" wheels. Go the 4.10's unless you plan on turbos in the future.

3.73 on 30.5" tires @ 70mph = ~2200 rpm

 

Why not get something in the middle???? Motive makes a 3.90 gear that will fit.... That is what I am planning on going with...

 

I have learned a very good lesson with getting gears in the past. So unless I can get a GM or AAM gear I am not going to get anything different. Every aftermarket gear I have ever had whined badly.

 

Hey Sky,
I just got an '02 ECSB, 2wd, 5.3, 3.73, & posi. It has stock wheels & tires. I am turning 2000 rpm at 70 mph. Stock tires, you should be about 1700 rpm, if remember a co-workers 3.23 truck. A friend has a 2500HD CC 2wd, he turns about 2200-2400 at 70 mph & gets 10-11 mpg w/ the 6 L. The engine noise is too much at that speed, an exhaust would get old at that rpm for me. I like the acceleration of my 3.73's but I would much rather have the 3.42 for my real estate sales duties. I feel the need to shift into another gear on the interstate. Most Silverado's I have been in must have the 3.42.
Drive around in 3rd to get a feel of the higher rpm for steady driving.
Good luck
Babyhauler
Montgomery, Al.

 

Hmm someone here from Montgomery. Well thanks for the advise. I will likely go with 3.73s and then work on the power side more so than the gearing side.