[ford38v8]

Bubba, just a couple more tips for when you find one and don't know if it works:

There should be no marks of repair, no serious kinks in the capillary tube, and only minor dents on the brass bulb. The fluid will initially be barely visible, and with a little heat to the bulb, show in the glass as a rich dark blood color, never
anything else.

As i said, a hot cup of coffee will prove the rise in temperature of a bulb. I have also used a match, which could get you hit in the head if you tried that with values today. Upon getting it home, a pot of boiling water on the stove will confirm the calibration: There is a scratch on the glass at the 212º F level. Upon installation, the glass is adjustable up and down to align with the temperature mark on the face plate of the gauge.

Stored incorrectly, a unit can easily have trapped bubbles, which will throw the reading way off. As the air is normally above the fluid, you can see how correct storage is important. Heat and cold cycles over time will correct this condition, and a faster method by mounting the unit solidly on a pole, then swinging it round and round rapidly with the brass bulb away from you. This is the kind of unit you can get a better price on!