I'm looking into trading up to a 3rd gen, but I want to stay with a 3:55 rear end.

First I know the 06's don't have the option of 3:55 does any of the other years.

Mostly looking at 03 - 04.4

Thanks

 

Not available from DC. Aftermarket: doubt it, but not sure.

 

To my undrestanding, all of the 3rd gens either have a 4.10 or a 3.73 gear ratios, mine is a 3.73.
Chip

 

Some guys get over the 3.73 by putting on larger tires and lowering it closer to 3.55. But the bigger tires kinda negate most of the mileage gain.

 

Yeah, I was going to suggest the 3.73's with a 285/70-17 tire. Give an effective ratio of 3.60:1.

 

Since you are looking for a 03-04.4 you will get the nv5600 as a 6 speed (as long as you get a 6 speed) or the 48RE (as long as you get an 03HO or any 04+) and the ratio is not near as bad as the g56 (which I have).. The problem mostly lies in the newer trans than the new axle ratio.. The auto is only a small amount greater than my 97 but the g56 6 speed is quite a bit higher. We have an 06 auto and my 05 g56 6-speed. The auto turns 2000 rpms at 72 MPH, the 6 speed turns 2100 at 65 MPH. Both with stock tires the 06 is a 2wd dually and the 05 is a 4x4 SRW..


Jason

 

Looks like I will be doing the 3:73 with taller tires,

Thanks, all

 

Not sure if it matters, but the 3.73 with lockup cruises at a lower engine speed than a 3.55 without lockup.

 

I am happy with my setup and the 315's. With the 315's there is a noticeable difference in low rpm power (less than 1500 rpm) compared to the OE tires, but for cruise this setup is great.

 

nope, not guna hapen... 3.73 is as tall as it gets.. one look inside and youd know why... just no room to go taller...
you culd throw a gear venders over drive on if ya want.. the .70 overdrive would knock it down to a 2.61 w/ 3.73's or 2.87's w/ 4.11's.. its only like $2300
or you can put on taller tires..

or...... learn to drive... ive got 4.11's and get over 20 mpg hand calculated...

 

About 1/2 of my miles are empty at 75 mph or abit higher. I get several mpg less at 75 than 60mph. If it were offered 3.55 gears would be tempting to me