Is the \"dual thermostat\" setup worth upgrading to? I keep seeing these on ebay- a dual 190 thermostat setup for 6.5 TD's. They say that the cooling was weak in the pre 97 6.5's. Since I plan on adding a turbo system to my truck, would this be a necessary upgrade? I've towed 8000 lbs at 65mph up some hills, and my truck has never climbed over 200, except when the radiator sprung a leak. Thoughts? comments?