I have a 91 2.1 WBX that just turned 300K miles on this past trip to FL.
The oil pressure is fine until the oil temperatures start to go on the north
side of 220 then it starts dropping proportionately with oil temperature.
Oil temperature starts climbing proportionately with outside air temperature
when the temperatures are above 85.  When it is 95 or higher outside my oil
temps can go 240-250 and pressure will drop to 30 psi at 4000 rpm.

Those of you have that have installed external oil coolers, how effective
have they been?  What kind of temperature drop can I reasonably expect if I
decide to install an external cooler when I pull this engine to "freshen it
up"?

Thanks for your comments, BobC