Several of the gauges stopped working in my 1988 IROC 5.0L convert.
I purchased another gauge cluster but a few things are different then the gauges I have. Could you tell me what car these gauges belong to?

What I have installed in my car:
Tach:
Yellow begins at 5,000 RPM, ends at 5,500 RPM
Red line begins at 5,500 RPM, ends at 7,000 RPM
Oil Gauge
Begins at 0 PSI, Mid line 30 PSI, Top 60 PSI

The Gauges I purchased:
Tach:
Yellow begins at 5,500 RPM, ends at 6,000 RPM
Red line begins at 6,000 RPM, ends at 7,000 RPM
Oil Gauge
Begins at 0 PSI, Mid line 40 PSI, Top 80 PSI

What are these gauges from? can I use them? I did install them, the tach is off but everything else seems to work, fuel, amp, temp, speedo

 

sounds like you got a v6 cluster,they have the 80 psi oil gauge.you can use them but as you mentioned the tach will read wrong

 

You can just swap out the tach.
If you had multiple failures on your old one you most likely have a bad ground or something on the circuit board on back. You could either try to fix that or possibly get a replacement for it as well.