I am a little confused.... off the line it feels a little quicker, but on the highway the Truck really hauls from 50-100mph the truck really scoots now. The top end feels so much better, Iam burrying the SPEEDO, is the truck that much faster or is my speedo off. Over all the pass power the the topend are great, I am very happy. What type of hp increase have I added if any?

Thanks in advance

 

What gear ratio did you have before?

 

3.31 I think is standard.

 

You did not add any horsepower with a gear swap.

Your speedometer is definitely off. With that change of gear ratio, your tach is off about 200 RPM's at 60 MPH...

 

I was not sure If I added power but the truck is more enjoyable to drive now. I definitely "feels" quicker..... and I can spins the tires from a stand still

 

B-Man, the tachometer is not "off." The tachometer is to the engine, not the transmition or rear end. But yes, the speedometer is off. Your speedo displays a faster MPH than you are actually going.

lets see here:

Old gears: 3.31
New gears: 3.55

3.55/3.31 = 1.07 or 7% more rotations.

Soo...

Going 60 miles an hour with new gears will READ about 64 to 65MPH on the speedometer.

 

I went from 3.31's to 4.10's and my speedo was off about 10 or 11 mph. If the Speedo was reading 70, I was actually going 59-60 mph. I had the Speedo corrected by using the custom tune chip by Troyer Performance. The 99 on up (I think) can be corrected by programming, the older models have to change out a small gear - others that are more proficient in this area can pipe in and explain how it is done.

The trucks take on a different personality when the gears are swapped out

Jeff

 

If you read my post, I said the speedometer is off, not the tachometer.

My reference to the RPM's at 60 MPH was meant to be understood as:

If, using the 3.31 gears, my truck turned 1700 RPM's at 60 MPH and now I have 3.55 gears, the tachometer will be at a lower RPM when the speedometer indicates 60 MPH.

 

Have you noticed a drop in gas mileage?