Well, it's either this or $450+ for a Torsen, Yukon, etc. RobertP claims there is very little, if any, shimming required for the factory Ford part, unlike the aftermarket one's.
Man, I thought someone in here would jump on it! It is still available, believe it or not.
97 T-Bird LX 4.6 - 80k miles
94 Supra TT Auto - street/strip car
04 CVPI- Brenda's car - 76k miles
95 T-Bird LX 4.6 - fully optioned, owned 15 years, 220k miles
96 Cougar XR-7 4.6- Brenda's car, owned 11 years, 187k miles
88 T-Bird 3.8 - first T-Bird, owned 5 years, 206k miles