do you do that via vacuum, I presume? I have a mech. coolant temp & oil pres gauge installed by the PO of my '79....they are generally rather nice gauges so I would not mind keeping them. They're currently disconnected as I've been re-doing the interior & wiring. Obviously, this would be a good time to change them to electronic versions if I were to go that route. Oh, and for general information, the oil pressure gauge was set up using copper tubing. I don't know if that's inherently more or less secure than the common nylon. There was some residue around the fitting when I was taking it apart/opening it, but I must say the 'action' of both those gauges is nice, especially coming from the 124 world where the factory oil pressure gauge is a marvel of inaccuracy.