I think my 05 Screw is geared to high, I am running 1650 RPM’s at 60 MPH and it’s sluggish off the line. I have been looking online at sites to buy some new gears and I have some questions. I see everything from 8.8 in to 10.75 in ring gears, which do I have?

 

You'll have to get under there and check the tag on the axle, it'll be rather obvious which ring you have.

 

You can find out by looking at the sticker on the inside of the Drivers door.

 

If i remember right under axle if it says B6 it meens you have a 3.73 .
The sticker is on the bottomn between the drivers fornt and rear door.
Hope this helps.

 

Your profile sez you've got a Lariat, and if so, you've got the 9.75" axle. All trucks that came with the 5.4 3V got the 9.75, the 10.25" is only available with the heavy payload package and it only comes with 4.10 gears.