Alright so I just bought a 97 f450 stake body 5spd and the gearing sucks. I mainly use the truck for hauling materials (dirt,mulch,sand,stone,pavers) and occasionally tow a small landscaping trailer or mini excavator/skid steer. If I'm going down the highway at 60mph, it's running at 2800rpms. The truck is drivin on the highway a lot and the fuel mileage is absolute poop. I don't tow a bunch of weight enough to make that a huge factor. I just need better mpg's around town and highway. Any idea of what gears I should run?

 

I'd go with 4.10s. Best of both worlds in my opinion.

 

X2 or even 3.73 will suit you well.

 

your F-SuperDuty ( it is not a F450) has either 4.63 or 5.13 gears in a Dana 80 axle. running 2800 rpm at 60 mph, i would venture to say you have 5.13 gears.
regearing that D-80 can get very expensive depending on whether you need a different carrier or not.

 

I'll trade ya for the sterling 10.25 3.55 ls I've got in my 1 ton parts truck lol

 

I appreciate yalls help. Even tho it's a work truck I want to do some stuff to it. I've built 100's of gas motors but I'm new to the diesel world so I'll be lurkin around the site for a while. Thanks again for the help

 

Their is a reason the F-superdutys have a 15,000gvw. The gears they came with is part of that