When I drove my air cooled 356 replica, I had an oil temperature gauge, oil pressure gauge and a cylinder head temperature gauge. (and, believe it or not, a dipstick temperature gauge!)
Some guys even have digital head temperaure gauges that monitor all four cylinders.

With the monster I usually keep a close eye on the water temperature, as the car can heat up in stop and go traffic (when the electric fan is off).
I consider the tach to be another gauge, and use it when I need it. I use it all the time in the monster, but seldom look at it when driving the Ranger (auto tranny). Also, the tach in the Ranger doesn't have a marked redline.
