High engine oil temps - oil cooler discussion

[SutteR]

My engine oil temp is very high when drifting, it can go up to ~140C and even though I use 10W-60 oil, it's not good for the bearings.

I have the stock oil cooler but I don't know if it is connected correctly on the sandwich plate. I'm curious if the stock oil cooler has inlet and outlet ports or both are basically the same. The sandwich plate has the inlet and outlet port but I don't know which one is which one.

Does anyone have any experiences with using double stock oil cooler - I mean connected them to each other? Does this conversion make any difference in the oil temps?
Aftermarket oil coolers with thermostat type sandwich plates are surely the best decision to cool down the oil but also the most expensive, that's why I'm asking this.