Gauge types & interchangeability

[Brad_Olson]

My '77 C10 has a fitting and tube for oil pressure while my '78 C10 has a sending unit. Does this mean that '73-77 oil pressure gauges are mechanical and '78-87 gauges are electrical?

Does anyone know if all '78-87 clusters are interchangeable? I'd like to replace my '86's cluster or at the very least the speedometer.

At a swap meet yesterday I found 2 clusters with the factory tach and vacuum gauge - $70 and $100. Unfortunately they also have ammeters instead of voltmeters so they won't work in my '78 or my '86.

Brad

[TrainD5115]

Yes to the first part of your question along with the fact that they are "amp" instead of "volt" which is another reason they are incompatible. The factory tach clusters with vacuum gauges came out of a big truck. Look at this article for more on these units.
http://www.73-87.com/7387garage/inte...achometers.htm