Apologies for hijacking the thread, but it kind of answers some of the questions I had planned!
Just been under the truck, I have disc (rotor?)front brakes and drum rears. Both axles have the same 5 stud pattern. And the rear axle also has sdjustable coilover shocks. So I guess it has been messed with LOL.

I'll get some pics tomorrow when it stops raining (if it stops, love this country) and start a new thread, entitled 'Guess the component!) LMAO!!