Yeah you had limited slip from the factory.. They must be blown out now..
There is two rebuild kits available..
1. for about $44 you can get a 8.8 LSD rebuild kit that you have to measure the shim adjustment yourself.. I like this kit because it comes with many shims and you can set it up tighter..
2. for about $100 ford sells the new updated 8.8 rebuild kit that comes pre shimmed.. as long as you don't mix the contents of the two bags then you just drop them in..
Plus you will need a bottle of XL-3 modifier to soak the clutches in before you install them.. let them soak for at least a half hour. Then you will need another bottle of xl-3 to put in when you refill it unless you buy royal purple that already has the friction modifier in it.
Ohh almost forgot.. the fluid is 75-140 synth.. and if you use a fluid without the modifier I suggest you under fill the diff slightly and put in a little bit of the modifier at a time until it stops chattering around corners. If you use too much it will cut down on the limited slip effectiveness.