S-10 Overhead Counsel

Hello all, I'm trying to add an overhead counsel(One with thermometer and compass) to my 1972 Monte Carlo. it was removed from a 97 Blazer that my friend wrecked and now I'm trying to find out where the wires go. I'm pretty sure that there is a sending unit for the thermometer and I think that the compass is all self contained. another question is... Where's the sending unit for the thermometer located on the truck? and where can I buy one? I doubt Auto Zone would have them, and I question wether or not I can even get it from the dealer. So, If anyone can help me out I would appreciate it.

Thank You,

Justin