Do the Super Duty trucks have the 10.25 or 10.5" axles? I asked a similar question before, but I'm still fuzzy on the issue. Maybe the 10.25 comes on the "heavy duty" F-150(?). Heavy-duty axles are important to me. I'm getting a 2-wheel drive Ford pickup within the next six months. Thanx. Jim

 

All of the 1999 and newer Super Duty trucks (single rear-wheel) have a 10.5" Sterling axle.

I think (not 100% sure) that the pre-1999 trucks had the 10.25" axle.

 

for the "most" part this is how it goes, can't go too far back but

f150 8.8
pre 99 f250-350 10.25
99/ up f250-350 10.50
99/ up f350drw 11.25

parts man