I had an
oil cooler on a 496 in Germany where my cruising speed was 80 mph (3.300 rpm), with accasional bursts to 160 mph. But mostly mountain trips with 80 mph, max.
I taped the cooler off and never removed the tape in 7 years! Even in 100°F heat (when I rarely drove the car). It had no thermostat.
You probably only need an
oil cooler when you operate your motor beyond 4.500 rpm most of the time.