3.42

I run 3.42 and it pulls fine.

 

Schlumberger had 5.13's i wanna say. 1900 at 65 with 11r22.5. 425/1650 isx pulled like a pissed off elephant.

Hardly had any emmision system issues either and they were 2011-2014. And we idled a ton. Never shut em off. I think super low rpm bean counter tunes is the root cause of after treatment issues

 

3.73 is the best good take off speed and still will run out of numbers

 

I was referring to the guy with the 2016 1500 Silverado with 37" tires. Doubtful that it's a powerhouse

 

Sorry, I wasn't paying attention evidently.

 

So can sommeon tell me the best way to gain a little more road speed. DD15 with 10 speed OD and 342 rears low pro 22.5 tires.To get 75 MPH I am turning 2100 RPM

 

Maybe you have one extra gear you don't know about? That does not sound right.
You should be at 1700

 

3.42 ring/pinion
40in tall tire
.73od
2100 = 101mph

The newer 10 speeds are .73 still, correct? Something don't jive.

For them to jive your truck would have to be 4.42s and im positive it doesn't have that ratio.

With 3.91 on 295/75/22.5 im at 1600 at 65 (.73) or 1400 at 65 in the big hole .62

 

Transmission Ratio RPM Calculator | Spicer Parts

 

I have 3.55 spicer rears and 10 speed eaton. The truck will run 70mph at 1600 rpm loaded. In the future I would want to replace the 10 with a 13 to keep the engine in optimal rpm range on some pulls.