I'm about 1700 at 70mph... T56 w/ 4.56's

 

You should have an RPO code that starts with a G

 

i got an 04 rcsb 5.3, i have the 3.42's and i run 2k at 70.....sounds like you got the 3.42's. from what ive seen in the past, the 3.42's are very common in the rcsb's. i usually see the 3.73's in the z71's and crew cabs.

 

I'm running about 1800-1900 with 3.73 and 275/55R20's

 

Lol. I run roughly 2600 at 70.

 

I'm running about 2700-2800 @ 70 and right at 3000 @ 80...no bueno

 

3.42's, 285/70/17's and around 1800 at 70mph. Your fine.

 

Sounds like 3:42. I have the same gears and do 75 at 2,000.