Originally Posted by Devil Car
Just because it isn't an FX4 doesn't mean it won't have a limited slip. My 4X4 without the FX4 package has the limited slip, as do many others that I've seen.
My 4x4 Off-Road package F-250 has a LSD in the back. My LSD was an option on the sticker along with the 4x4 Off-Road package. pretty sure the FX4 package didn't come out until '03. Up until '03, the trucks were either 4x4 or 4x4 Off-Road and I think the Off-Road package was Skid Plates and a Sticker.
You'll have a hard time finding a '03 7.3 FX4 as the 7.3 was offered in limited quantities in '03
Manual Locking Hubs have nothing to do with the locking action of the differential. It just means you have to get out and turn the knob to go 4wd instead of turning the knob and a vacuum line causes them to lock.