I have/and had CJ5s since I started driving.....1- 8cly (304).......5 6cly (258) + '46 Willys (cannot count him in on this)
My O.P. Normally runs 40-60 PSI (New up to 8 years as a rule of thumb, depending on YOU!).......As stuff wears down, I have dropped to as low as 15 PSI on my rigs...............before I took drastic action!
I have been told 4 PSI will lubricate an engine.....But I will never let mine go that long!
Here's what I would do if you haven't done it yet..........Take off your sender, replace it with a Gauge that uses a Tube to pick up oil PSI (mechanical gauge)----NOT electric P/U and electric Gauge (I suspect you have now)
This can be temporary, hook it up, close your hood on the tubeStick it in your window.
Observe the Mechanical Gauge while drivingI, Myself TRUST a Mechanical guage More!!!! (reading is direct, not encoded and decoded on both ends)I usually encase the tube in fuel line to protect it.
If it reads better than what you had, install it permanently (Pick out one you really like, when you purchase this as a "TOOL")......the small parts connection parts within, are available separately.
I do not know what you used for a pumpOn CJs a "High Volume Pump" is available..........And they really up the presssure in a worn engine.
Heres one----cheaper than stock, the way I read it, for yours! they offer 2 other pumps----investigate later!