There's a built-in 140*F thermostat in the Rx7 cooler, as well as a 180*F thermostat in my Mocal adapter. They're not both necessary but I'm too lazy to delete one of the thermostats.

 

hustler, is your outlet hose at the top of the oil cooler, or the bottom?

 

If you saw my setup at MSRC the oil temperatures are getting no higher than 230F-240F and that is at 325 RWHP albeit in an LS1. The ducting in front of the oil cooler made a big difference. Loosely speaking, all of the incoming air in front of the oil cooler is forced through the oil cooler. It cannot 'spill' around the sides. Before I added the ducting the oil temperatures were much higher, all else being equal.

My oil cooler has an inline Mocal thermostat.