Been looking out here for a bit and I'm not having any luck. I'm trying to find out what rear differential I have. The Rig is a 1999 F350, Super Cab, 4x4, Dually, XLT, 5spd manual, V10 hauler built in Jan 1998. I know it isn't a 10.25" or 10.50". I'm left with two different Dana 70s and two different Dana 80s. Will anyone help? Thank you so much!

 

F-350 DRW trucks use D80 rear axles. Check the door sticker or the tag on the pumpkin for the specifics of how the axle is configured.

 

I already looked for the axle tag. Nothing there. What will the door tag tell me? Not much from what I remember. Thanks!

 

Gear ratio and if you do or do not have limited slip, for starters.

 

I'll do some research. Thanks.

 

Well. Axle 61 means I have an Open 3.73. Got that info from dieselbombers.com. I'm inclined to go with the Dana 80 as my axle. Is the Dana 70 for SRW super duty's? I don't know. Just trying to figure out all these things in my head. Knowledge is wonderful! Thanks everyone!

 

SRW trucks use a Sterling 10.5 differential.

 

The D70 was used in the van's. If you have any doubts about your ratio, jack the rear up and turn the pinion while counting the revolutions of the tires.