This was what I found in the oil pan. I cleaned out the remains of some of the residents of the mouse condo in the valve gallery...

What is the function of the knob on the oil pump?

Adjustable oil pump. Turn in to increase oil pump flow, turn out to decrease oil pump flow

if the engine was running before, with warm oil and rpm at idle, and pressure was good then dont change it!
dont test it (as i did as i was curious, but i made a mistake: i used cold (thick)new engine oil and tested and adjusted the oilpump to "good" rate (what i thought, but ...... when engine was running, and oil warm, and a bit deluted with gasoline, the pressure is now a bit low when idling..... and i have to take all these parts off to adjust it again and make the pressure higher.
if you test it than try it with gasoline as it is thinner like hot oil.

"truckun95" wrote:

Adjustable oil pump. Turn in to increase oil pump flow, turn out to decrease oil pump flow

Thank you. Not touching that till we run some new oil in the engine...
Where can I get an oil presure gauge with the old style face that fits in the dash?

Can I use modern oil?
Rotela 15-40 or Delo ?

better oldstyle single grade , non additive oil , as new oils can have "bad influence " on babbit bearings

Ok 30W in the oil pan.
Mean while some photos.

While torqeuing head bolts. #1 started slipping from 30 to 40ft lbs. All other bolts held 40 lbs.
Will have to change out stud if it leaks, or when the head comes off next time.

Assembled head.