In a Ford 9.75" 4.56:1? There's nothing above 4.11:1 made in the US (the Ford brand) that I'm aware of.

Not only are most of the brands made in China now, I think many all come from the same factory - Yukon, Motive, and one or two others. Richmond used to be the best and Made in USA 20+ years ago. Now it's a hodge-podge - some stuff is made in China, some Italy...they might have a few sets made in the US still.

US Gear makes good stuff, but nothing in 9.75.

 

I think I would go to a 3.73:1 or 4.11:1 setup.

I need more out of the hole and dont care about top-end, it is a truck after all. However, I dont want to "kill" the highway mileage.