Hello;

Can someone please tell me what the engine compression PSI should be for a 1990 Pontiac Bonneville LE, (242 000Km).
I bought an engine compression tool from a garage sale two weeks ago for $7.00 and every time I crank the enging up the needle cranks up to 100 PSI but when I reset the compression tool the needle clicks up to 60 PSI. 60 PSI shows as being in the red-zone Is the tool broken or what? There was no oil on the spark plugs so the rings are fine...the spark plugs looked normal...the engine is fine. I feel that 60 PSI is fine. Is it?
I'm sure that this must be a question that comes up often but I don't have the time to scroll through the past 1000 posts to see when it was last asked.

ALSO....is there a SPARK PLUG for sale that also shows the engine'* compression?