If you have the filter that you recently took off carefully cut it open and look for signs of a bearing material or other foriegn material. One thing to also consider is the
oil pump being used for your application. With a remote filter be absolutly sure the
oil is flowing through it the right direction and with an
oil cooler and related lines it may be necessary to utilize a high pressure or high volumne pump because of the additional amount of oil that is being moved through the system. Check with your engine builder for recomendations in hose size, use as few 90 degree fittings as possible as they restrict flow considerably, and keep the hoses as short as possible. The engine needs more pressure than you indicate. Also eliminate the possibility of a bad gauge.
Good luck
Rick