According to the build sheet (VIN decoded using FTE link), I should have 3.73 gears. But this picture and the general performance of the truck leads me to believe that I might be running different gears. Any clues other than I look at the stamping when I do the differential service? There are no tabs on the diff covers to confirm this. Before someone comments, the truck is running on cruise at 65. The speedo shows less 'cos I am running taller tires than stock (34" vs. 31")

 

 

Guess, I have the wrong info then. I thought the RPM being below 2K meant, I was prolly at something higher than 3.73. Would the RPM be higher than 2K if so?

 

You have it backwards in your mind, Prakash. You are right where you should be for 3.73 and those tires. I run about 1900 RPM for 67 MPH. That is for 33" tires.

 

Thanks Tom and Mike, for setting me right

 

I agree you have 3.73s. I'm running a 295/75R16 and the rpms and speed are very close.

 

Yeah, deeper gears (higher numerical value) will have it turning more RPMs at a given speed. Back when I had my 4.88s and a set of 32" tires it would turn 2280 RPMs at 60 MPH, now with those same gears and the 35" tires it spins at 2055 RPMs at 60 MPH.