Any Ford 9 inch Experts?

I've been looking at using a Ford 9 inch for a future project but I haven't been able to find much information online about which models came with trac-lock stock. I want to use a 31 spline version so I'm assuming I'll have to look at a F150, Bronco, or E150 (as those are readily available in our yards). Did any of these come with Trac-Lock stock or were they just options that buyers could get?

Thanks!

If you're willing to look at the 8.8 instead, you can tell if they have limited slip by looking at the axle tag. If the third character is an L, it's LSD (and the first combined with the fourth and fifth tells you the gear ratio). I know all 8.8 Mustang diffs had LSD, but I think they're all 28 spline. Explorer 8.8s are 31 spline, but I don't know if they all had LSDs.

EDIT: Reading somewhere that 8.8s with drum brakes are 28 spline, w/disc brakes are 31. Not sure the validity of that info, though.

I think I may be just limited to the 9in. I've heard the 8.8 will break with 500 hp at the wheels/ sticky drag tires.

In reply to cheechthechi:

9" will break at that power level too without upgrades.

cheechthechi wrote: I think I may be just limited to the 9in. I've heard the 8.8 will break with 500 hp at the wheels/ sticky drag tires.

There are a LOT of guys in Mustangs pushing more than that through 8.8s on slicks.

Heck, modded Terminator owners are pushing that through the IRS version of the 8.8.

Anymore, the only reasons I could see to go with the 9" are if you already had it, if you're mucking with it enough that you really do need the drop-in diff, or if you're making 4-digit kind of horsepower.

2nd character on the tag will be an L if it's a trac lok. They can be 31 or 28 spline. There are variations in the cases between material (best are standard or the N cases - WAR or WAB cases are not as strong) and big bearing vs small bearing. The short of this - finding the strongest case with 31 splines and trac lok in stock form is not super common (just the heaviest duty - mid-late 60s 428cj equipped stuff...). More likely to find a modified one from an offroader. Every junk yard has cheap 8.8"s with discs.