Did a lot of searching and I'm figuring it's the dreaded front O-Ring. BUT! I would like to state some facts before I tear into this.

Using an aftermarket mechanical gauge.

I am using the atkins thermal pellet so we can eliminate that as an issue.

Cold start up (I use the BAC to bump idle to 1500 on cold engine) I am at 70PSI, so some good news.

I suspected my oil cooler t-stat and just replaced the cooler, but it's still the same.

At idle, around 900RPM I am seeing 10PSI oil pressure. And normal driving (2-3k) I am seeing 45-50. After much searching I'm reading that this is a good indication of a failed O-ring. This sucks as I only have around 300 miles on my rebuild. I have replaced the o-ring in another engine previously, so I am sure I built this engine right. But if it failed, it failed.

However, I found a post from the late Icemark while searching indicating that ideally you want 10psi for every 1000RPM.

Is it so terrible to run the car with these oil pressures?

Last but not least! It's finally spring here in NY and the weather was nice and warm today. I was running 10w30 for the winter and still have it in my car. I am going to change it back to 20w50, will this bump my pressure?

 

i woudl def. change it back to 20-50 then recheck, sometimes that difference can bring it back into spec

 

My engine has almost identical oil pressure (I run 10w/30 year round) and has for the last three years.
I wouldn't worry too much.

 

did you rebuild the engine with new bearings or did you reuse old ones?

 

thats right, in order to have pressure you have to have restriction

 

Thanks for the responses, I've been busy moving so I couldn't check in for a bit.
Hopefully when I get a chance I will switch to 20w50 and see what happens. As long as there is some pressure I shouldn't be too worried. I only drive the car on nice weekends anyway, 300 miles or so the past 8 months

I did not replace any bearings as they were within spec, and very little or no copper showing.

Thanks again.