Most popular rear end gear ratio with 5.3/6.0 engines?

[K85 Octane]

I'm putting a 5.3 or 6.0 with 4L60 into my '68 C10. Wondering what gears are used in these trucks. Like a 1500 Chevy mid 2000s. Wouldn't mind matching what factory uses, since this will be a DD, but since I'm building a rear axle before I have the motor, figured I'd ask you guys.

Thanks y'all

 

[Babaganoosh]

Depends on the years, up until 2011 you either got 3.42's or 3.73's as a option. In 2011 they went to 3.08 gears.

I know my buddy's Trail Blazer SS had 4.10's but that was a special order deal.

 

[82355]

I'd say go with 3.73's. They are fairly high winding engines, and you have overdrive.

Martin

 

[76zimmer]

my 99 2500 likes the 3.73's on 31" tires and OD
The mileage don't agree though!

 

[AJs72K5]

2000 Silverado 1500 with a 5.3 had 3 choices from factory...I ordered mine back in the day. 3.42, 3.73, and 4.10.

 

[blazinzuk]

I'd say go with 3.73's. They are fairly high winding engines, and you have overdrive.

Martin

This 3.73s won't get you sky high with the rpms but keep some serious gearing grunt at work for ya

 

[y5mgisi]

My 12 has 3.42s and the 6l80e it does like 1500 rpm at 60mph. You would likely be running smaller diameter tires than me, and you won't have the double od of the 6l80e trans. So, for you, I would do 3.42s.

 

[jake 03]

3.73 or 4.10 are the way to go. They are high winding engines and are more efficient if they are breathing vs lugging. My 03 Silverado xcab with a 5.3,3.73 gears and 29" tires could easily get 21-22 mpg at 75 mph.
Now my tbss has 4.10s and would probably be faster if it had 3.73 or 3.42 gears. Right now it will just spin at any speed less than 60 and is gearing limited to 145mph (in third,od isn't strong enough) and it will only get 17-18 mpg at best.

 

[K85 Octane]

Roger that folks

I think I'll go with 3.73 gears. My S10 runs 3.42 (apples to oranges I know) but I think 3.73 gears for the C10 will give it decent mileage, snappy response, and ability to tow some trailers from time to time.

 

[Babaganoosh]

What size tire you going with? I would agree on the 3.73's.

 

[sweetk30]

play with this first http://www.grimmjeeper.com/gears.html

and my 2wd build I am doing 5.3/4l60-e/3.73/29.1 tire dia and get 65mph = 1960rpm

some reading I have done guys say the ls motors like to be lugged just a tad for a better power feal . so that's 1 reason I went 3.73 over 4.10 . other was its what was in my used axle I got cheep

 

[y5mgisi]

I'm sure you will be satisfied with the 3.73s.