oil pressure on a 242 Chrysler flathead

[Handyman57]

I have noticed  that the oil pressure  will fluctuate  between  40 to 20 lbs even when holding the  throttle  a steady 800 rpms,or higher, is this normal, or is the pressure  relief got a problem?

Thanks 

T

[misterc9]

I would probably hook up a known good mechanical gauge directly to the engine. Then see if it really is fluctuating.

[c49er]

Sometimes the floating oil pickup adjustment tangs are out of calibration.

Even though the oil level reads full the pickup float is sucking some air.

I recently fixed this on a 50 chrysler 8 having fluctuating oil pressure at the full mark....added a quart of oil to figure it out.