but have tried to avoid the usual overheating problems with some success. Number 1 is the exhaust elbow, which can coke up and cause back pressure on the water injection. And the cooling water output itself. Number 2 is the usual heat exchanger, which needs to be rodded out every 5 years or so, depending on your water. And cleaning out the rest of the copper plumbing. Number 3 is the oil cooler (don't know if you have one) that also needs servicing. How much are you overheating? Even turning on the gauge lights will cause the apparent temperature to go up a bit because of the voltage drop to the gauge. And of course there is the thermostat itself, but not usually the problem. Other engines similar to mine run at 175-180 deg at 2500 rpm, and have enough reserve that they don't overheat at higher rpm. So no "prone" to overheating. There is actually a plug in the cooling system that some mechanics leave out that makes them "prone" to underheating so the mechanics can make excuses for their negligence. After 4000 hours or so, still runs at 175-180 deg, Oil Pressure at 45 psi. But, of course, at that vintage could explode tomorrow. ;) If your oil pressure is also dropping, you may actually be producing excess heat. Smoke?