oil pressure reads 20 at 3000 rpm and doesnt go much higher on this 74 with sc engine

what should the oil pressure be at for a 74 with a sc engine....it seems low...could this be due to differences in sending units...do these cars have pressure problems and if so what causes it...just looking at buying this car with low readings...virtually zero at idle on the gauge and 20 at 3500 rpms...and 25 at 5000 rpm...it is a good deal....thanks

I was in the same boat after rebuilding my engine and was very worried about low oil pressure in these engines. From what I have learned, it's OK if the pressure is down around zero at Idle but it should go up with the revs. The specs I've been given are 10 pounds for every 1000 RPM and min. of 57 pounds at 5000 RPM. If your readings are when the engine is cold then I think you have problems and it even seems very low for a warm engine. At idle my car goes from 50 pounds cold to under 10 warm.
hope this helps

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Guys:

Use the "Search" function above, and type in "oil pressure". You will see lots of "strands" on this subject. Nothing has changed since then.......Andras