400kpa/60psi vs 550kpa/80psi gauges

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unruhjonny

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It appears as though I am doing something of a crash course in these trucks;
I was going to buy a "replacement" set of gauges for my truck, to replace the faded needles and gauge faces, but just as I was pulling the gauge cluster I realized that the cluster I was grabbing had an oil pressure gauge which went to 550kpa (I'm Canadian; I looked, this is about 80psi), while my oil pressure gauge only reads to 400kpa (roughly 60psi).

What year did this change?

Or

Do the gauges change based on engine or package?

My brother was wondering if I had "big block" gauges... if that is even a thing.

This is my cluster:
full


The needles and coloured parts on the gauge face are just as faded as they look in this picture.

Thanks in advance for any advice and/or information that can be offered.
 

someotherguy

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Most likely you are looking at a cluster from a big block truck. In general, but not in every scenario, the small block TBI clusters go to 80 psi on the oil pressure, and big blocks to 60 psi. There are exceptions. The earlier "moonie" clusters seem to go to 80 on that range regardless.

What year is your truck?

Richard
 

unruhjonny

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unruhjonny

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although I am a newbie, I wonder if there is something more to this;
A friend (owns a 1990 SS454) explained to me the "moonies" bit, and told me that all the moonies oil pressure gauges went to 60psi/400kpa;
He also seemed to suggest/confirm (but wasn't 100% sure) that the 1991+ gauges with 60psi/400kpa oil pressure were "big block" gauges.

Then I found this weekend a set of gauges that are a dead ringer for mine, on a 1991 truck!
Now either I had a seriously stupid streak of dumb luck, or there is a pattern here.

I am wondering if this is more likely:
1988-1990 'moonie' gauges = 60psi
1991-1992 gauges = 60psi
1993-1994 gauges = 80psi

I did look into this from another angle, and found from what I saw that the senders didn't differ for the gauges, meaning that there is only one sender, regaurdless of gauges.

Does anyone know if at some point the small block trucks started getting a higher pressure oil pump to justify the 60psi to 80psi gauge change?

(Just trying to wrap my head around things)
 
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MSCustoms

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Ive been wondering if they are 80 psi sensors. My oem gage would show about 60 psi at start, 30 psi at cruise and 15 at idle. My new gage shows 45 psi at start, like 25 psi at cruise and 10 at idle. If you take a percentage, 60psi on a 80psi sensor, you get 3/4 on the gage which is 45psi on my 60 psi gage with a 80 psi sensor.
 

unruhjonny

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Ive been wondering if they are 80 psi sensors. My oem gage would show about 60 psi at start, 30 psi at cruise and 15 at idle. My new gage shows 45 psi at start, like 25 psi at cruise and 10 at idle. If you take a percentage, 60psi on a 80psi sensor, you get 3/4 on the gage which is 45psi on my 60 psi gage with a 80 psi sensor.

That's a really good thought!!

I actually bought a stand alone oil pressure gauge to verify the real oil pressure;
If these service replacement senders are in deed 80 PSI units, that right there might solve my "low" oil pressure problem... (crosses fingers)
 

mruysch

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Bought that truck when I was 16 in 2002 and in 2013 #2 connecting came through the block. been parked ever since
 
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