That makes sense. Comparing the roller rockers and roller cam to modern engines; those guys often report 10-15psi at hot idle.
Prior owner spent money on parts; so I don’t doubt he got the best or largest flowing pushrods, rockers arms. Just worried me about proper installation Of those parts.
I don’t know if he did the engine work or not. Lack of kickdown cable. Using standard amp alternator on a fuel injection, electric fan and car speaker amp. Blue rtv to seal up pcv, breather grommet, and valve cover plug grommet. Looks like someone even hand cut a small gasket for the oil pressure sending unit and then smeared blue rtv on it.