Gentlemen, thank you all for your guidance. I emailed Roush Performance Engines with the same question at the head of this thread three weeks ago. Mr. Mark Yagelo responded quickly, but SBCGLOBAL didnt deliver his response until recently (sigh). The Roush response was:
Generally speaking, we'd expect 25-30 PSI at idle with the oil hot. From there, you need 10 psi/1K of engine RPM. So at 4K RPM, min PSI would be 40 and at 6K RPM, you want to see around 60 PSI. Max oil temp for normal operation is 230F and water is 210F.
I told him the previous owner used Mobil 1 10W-30, and asked his thoughts on
oil for this engine in a weekend cruiser. He said:
10w30 conventional from a reputable source. I like Castrol GTX in my personal vehicles.