motor heating up at higher rpms

[THEFERMANATOR]

Also check your heat exchanger. I know that the early 3.7L's came with a smaller heat exchanger that had problems with overheating. Also how old is your exhaust elbow where the raw water dumps out? If it's more than 3 years old it may be getting blocked up. Check for leaks first, and then look for flow restrictions. Also check your impeller in the outdrive, they are known to spin the hubs at high RPM's.