416 low oil pressure at idle

My sons 416's issues continue !
the hot idle oil pressure is only 10-12 pounds - this is with engine temp 180-190 and idle around 1000 rpm, using Valvoline VRI (NSL) 20/50 and Napa Gold (Wix) 1085 filter.
Initial startup the pressure is 40-50 but drops to 10-12 when hot ??

this is a new engine with less than 200 miles on it !

Spoke to engine builder - he didn't seem to be too concerned but i am.

Pulled distributor last night and confirmed the oil plug was inserted in valley, pretty positive oil shaft/distributor gear is the hardened tip pinned version.

What should i check next ?

any help or comments are greatly appreciated

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