In my '31 I have a coolant temp gauge in a single gauge holder that attaches under the instrument panel. Pain in the *** to replace after removal.
I am thinking of converting to a two-gauge panel on the steering column with tach and temp gauge. My ideal tach would be 3" or so, 270 degree swing, and 0-5000 rpm. Haven't found it yet (they do appear to exist for diesels, though). If I do I'll make a panel with that gauge on the right and coolant temp on the left (standard 2" gauge).
On another note: I put in a 6V+ to 12V- converter and run it to a 2-hole cigarette lighter adapter. Has anyone run into a panel with a cig adapter and USB ports? Or know a decent vendor who might make one?