It's painful to be as ignorant as I am on these issues of great importance. Basically I don't know if my engine (fe390 w/OEM 390 heads) has restrictors or not.
Oil pressure is not as high as others, mine cold is at about 50psi and warmed up at temperature will drop to 25-30 while cruising. Makes me suspect I may need some restriction in the top. Other than that I have no other indication...I have not run the engine and physically observed
oil flow. Is there only the one restricter per side to install or are there restrictors for each rocker shaft? If I open my valve covers and look to see, what do I need to look for ( I saw Pat's pic) and is this something you install while the engine is together or is that a no no. I'm sure I'll have more questions later. Thanks, John