'81 SC, normal temp gauge readings?
 

Picture kinda says it all, but here are my gauge readings cold and hot. When I got the car I had no change in readings cold/hot so I tested the gauge and wiring by grounding the green wire at the sender end, which pegged the gauge (as I understand it should.) So this indicated a failed sender. Replaced the sender with the correct version from our host, and now it shows a difference... sort of. Normal?

http://www.evan.com/minerva/cold_n_hot.jpg