27
« Last post by bd on April 11, 2024, 11:01:41 PM »
You're probably correct in your summation of an 80 PSI gauge in the original cluster.
FYI - The GM oil pressure gauges and senders are electrically identical. All of the senders have the same 0-60 ohm resistance characteristics; gauges likewise are electrically and mechanically identical except for the face markings. The differences between applications are in the spring rates of the senders and the face markings on the gauges. In later years, many of the gauges had "Low" and "High" oil pressure scale marks in lieu of 0-60 PSI, 0-80 PSI, or 0-100 PSI. This was done to minimize inventory since any of the three senders would work correctly with a generically marked Low-High gauge face. If you inspect the sender stamping as previously discussed, you will know exactly which gauge suits the sender. For example, I use a 100 PSI sender in my '87 R10 with 5.7L engine and a "Low-High" gauge face because it runs 90 PSI cold and 50 PSI at normal operating temperature. If an unfamiliar driver didn't know it was a 100 PSI sender, the gauge indication would appear the same as any standard 60 PSI gauge.
The take-away here is to make sure the sender stamping matches the gauge markings. So if you install an 80 PSI gauge, use a sender that is stamped 80 and you will be rewarded with an accurate reading. The caveat, however, is that not all aftermarket senders are stamped per OEM protocols. Shrug.
1
Recent Posts