The oil in my car is 1500 miles old, and it was around 1/3 of a quart below the max level on the dipstick. My oil pressure seems about 20-25 psi lower than normal all across the board. At start up it's 40 psi at idle (instead of 60), mild acceleration once warm barely taps 30(used to easily jump to 55), and idling when warm seems to net me right around 3-6 psi.

My oil pressure normally never gets below 29 or so even when hot at idle, so something has changed, and changed all of a sudden. Im thinking either I've got a bearing going bad or the sending unit is toast.

But the gauge reacts normally to acceleration and rpm's and such, it just reads a lot lower than it always has up until this point. If it were the sending unit, would it be more of a complete failure? Would it just read 0 psi most of hte time?

 

Either change the sending unit or connect a hose with a gauge on it and verify the pressure.
If the pressure (measured with a manual gauge) has dropped suddenly it may be as simple as a stuck bypass valve in the oil pump...
or,
It could be a good reason to start building a new 355 or 383...

 

change the sensor ,[ above oil filter ] first . mine was doing all sorts of goofy
$hit . changed sensor , much better now . high oil press. , is not good . flow is what matters . don't think you have that problem . use right wt. oil and change and flush on a regular basis . 30 psi +/- is o.k. , don't use heavy weight oil to raise oil press. . hope this helps , be careful with the connector to the sensor , brittle plastic .