Slant 6 oil pressure woes…

I thought I posted this earlier.... not seeing it now.
I had a 64 225 and trans here recently, actually fired it up while sittin on the trailer. Didn't run it but a minute or 2 each time, feeding it by dribbling gas in the carb throat.
I split the trans and put the engine on the stand. I drained the oil, and what I got out was the consistency of gas and blacker than tar.
I then pulled the pan (glad I hadn't flipped the engine at this point) and it was full beyond the top of the pickup screen with a gray mayonnaise consistency, sludge. I had sold the pan,
(front sump 60s truck pan, first front sump I'd ever seen on a /6) so had to clean it up for shipping. At least for that purpose, I'm glad it cleaned up easy and wasn't baked on.... I actually traded pans with a guy just to have something to keep the motor sealed up.
I didn't notice any knocks, only that the oil sending unit had been oozing out the thin crap that drained out thru the plug the whole minute or so it ran each time. Oozed out right at the crimp between the metal and the plastic. Once I saw the true contents of the pan I was glad I didn't run it any more than I had.... I'd be willing to bet that motor didn't have much oil pressure..... I took off what I wanted, and sent the motor and trans down 2 different roads....
you may be dealing with the same issue within your pan.