ok, so yesterday I swapped out the K&N filter for the same size (3" diameter) AC Delco PF61 (I have headers and the wider filters don't fit). They didn't have the Wix 51045 in stock. I topped off the oil level and fired the car up for the first time in 3 months.
Oil pressure old was immediately good, just above the hash mark at about 63+psi. See first video.
Then as I drove and warmed up the car, pressure went down to just above the 37psi hash mark at 3,000 RPM just as it did with K&N filter (so maybe 40psi, see second video).
Hot oil pressure at idle is around the first hash mark, so about 13psi.
I guess this is just a characteristic of the slick flowing Amsoil over the Dino oil with Zinc additive that was in there before.
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Adam
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1964 LeGTO
469, M21, 3.42
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1968 Pontiac LeMans Convertible
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