I doubt the
oil cooler blocking the rad. is causing any problems if it's fitted entirely inside the lower scoop like most. Unfortunately, there are so many variables that it's difficult to diagnose without changing one thing and testing, while holding all others constant.
I have a Griffin radiator, with
oil cooler (no
oil thermostat), electric pusher fans manually activated. My 427 SO runs a constant 160 at cruise, and 190 at idle with fans on. Oil temp is consistent with water temp, but I do cover the oil cooler with a homemade fiberglass cover in cooler weather, in order to get the temp up to proper level.
PNJ, if you got hotter with oil cooler, I would suspect the oil thermostat over anything else.