How heavy do you tow? The 4.10's are going to tow better. The 3.55's are going to get better mileage...

If you don't tow heavy, Swap to 3.55's. But it's not going to pull any better than 4.10's.

And that's a factory tire size. Jumping from those to 33" or 35" tires would help you out quite a bit on the 4.10 gears.

 

yukon makes gears for it. you dont need to buy new axles.

 

Site? Gear ratio's available? Cost? I would think 3.73 would be perfect middle of the road choice, if available?

 

If you are swapping gears to get better fuel economy and better highway speeds. I would just go the 3.55

 

Let me google that for you

 

And?

 

And what? Do you not know how to search anything for yourself?

 

I've towed between 5 and 6 tons on a 35ft gooseneck with both 4.10 and 3.55 gears in an SD. The 4.10 were better for starting off the line but the 3.55 were better for "up to speed" pulling. The 3.55 also were better for day to day unloaded driving.

 

Do you mean 3.73 for the SD?

 

Yeah what ever they had that was more of the "highway gear"

On a side note I checked out Yukon Gear and most of the gears are avaliable in 3.55 or 3.73 for the F250 1993 and newer. The only thing was the IFS Dana 50 was reverse rotation, is this correct?
Rear 10.25" link
Ford F-250 3/4 Ton Rear Differentials Ford 10.25" Ring & Pinion Sets Auto Parts: YG F10.25-355L, YG F10.25-373L, YG F10.25-411L, YG F10.25-430L, YG F10.25-456L, YG F10.25-488L, YG F10.25-513L, YG F10.25-538L, YG F10.5-355, YG F10.5-373, YG F10.5-411,
Front IFS Dana 50 link
Ford F-250 3/4 Ton Front Differentials Dana 50 Front, IFS Ring & Pinion Sets Auto Parts: YG D50R-354R, YG D50R-373R, YG D50R-411R, YG D50R-430R, YG D50R-456R, YG D50R-488R, YG D50R-513R, YG D50R-538R,