416 low oil pressure at idle
sounds like it was put together with loose clearances
If it's been consistent since built, this may just be the reality. I understand the nervousness, as i'd like more pressure also.
It sounds like you may have a decent relationship with the builder, so i'd just let him know, since he's ok with it, your sons gonna let'er rip and if a issue comes up.....it's coming right back to him for a full repair. That may get a different response from him, and if he's still cool with that......let it eat. :thumleft:
P.S. Like Dave eluded to, you may try a straight weight, 40 or so, and see if if it acts the same only a little higher pressure. That to me, would probably confirm the wider clearance theory.
