I have no personal experience with them but I know alot of people that have used them on 8.8's in mustangs. The majority of the people I have talked to said they leaked and some were unable to use the self adjusting mechanizm for the brakes.
I have been told the way to go is to have 9" ends welded on to the 8.8 axle.
On drag only mustang they are ok. They leak but they are ok.
On a cornering car they leak like crazy and are not advised becouse they where never meant to deal with the lateral loads of corning.
Putting them on a truck would be even worse. They would leak like crazy and if you offroad alot (lots of lateral loading) you would either breake the bearing and have an axle walk out, or the axle would unpress itself from the bearing and walk out.