Good question. My machine shop guy is a Ford man, and he remembers Ford had two sending units, one said 80, and the other had 100 on it. I'd like to know myself. New sending units today don't have that on them.
Gotta remember the older Ford vehicles had dash gauges that read...L(low)Normal(which was most of the gauge sweep)and H(High)Nobody really knew what any of that meant but they had full "instrumentation". Like most electrical gauges....highly inaccurate.
Most of the Mopars I've owned have similarly marked gauges, oil pressure and temp, and amp gauges with the high end and the low end with or without numbers, a center mark, or a "normal" range. You have no idea what any of the marks are suppose to mean. I don't hold much faith in any factory gauges. Gene
