Originally Posted by brak876
... In the end will the 4.0 ZJ springs give any lift to a 4.0 XJ 1996 4x4.
Maybe, and maybe not. As you have read, it depends on the donor.
An easier and more reliable lift method is to buy lift coil springs, or lift coil spring spacers. You will end up with the expected amount of lift. IMO used coil springs are not much cheaper than new coil springs, and you run the of risk wasting the time and effort for an unknown lift height, or maybe no lift at all.
After about 2" of lift you should do something with the track bar, either re-drill the mounting hole, or get an adjustable one.