My 2056 race engine currently has the stock oil cooler in place, and a rear mounted oil cooler with fans that picks up from the oil filter housing. an adaptor on the oil filter allows the oil to circulate to and from cooler pretty well.
I have not had overheating problems. Willow Springs on a warm day, oil temp got to 210. But, if I do an enduro, I think this system might not cool enough.
Question is, who has a front mount oil cooler on a 4? Did you retain the stock oil cooler, or did you use the stock cooler in and out for the new hose connections?