I just had these installed with a Eaton posi unit in my 98 Expedition 4x4, 4.6 with 33x12.50's. Its like someone released the parking brake. The difference in driveability is great. Haven't floored it yet, but I'm very happy with how it drives so far. I used a 23 tooth speedo gear from Steeda and the tripometer is 1.5% fast.
I want to thank everyone here at this site. I did alot of searching through old threads before doing this and all my questions were answered. Also questions I hadn't thought of.
F150online is great!!