What about high oil pressure. My factory zero time O-235C1 is running
at around 90 psi in cruise. This is at the very top of the allowed
range.

Oil Pressure Limits - (Normal operations) Minimum 60 p.s.i. Maximum 90
p.s.i.
(Idling 25 p.s.i.)
(Starting & Warm-up) Maximum 100 p.s.i.

Is this a problem?