Hi Tobin,

It would be a good idea to install an oil pressure guage to monitor the
situation. Even thought the mechanic overhauled the press relief valve
(which, BTW I had thought was hidden by a plug, is that so? and did he have
to drill it out then reseal?) it may not be trustworthy. Even with lighter
weight oil the pressure can still be fairly high (over 100 psi) when engine
first started and oil pressure low.

Alistair