I have a 2008 f350 4x4 all stock that is driving me nuts.I can drive all day around town in stop and go traffic and i can even floor it and all without any problems and the truck runs great. Now when i take it on the freeway at 60-70mph constant even with the cruise control on it will say reduced engine power after about 10min of driving. I will pull over and turn the key off and let it set for about 10min and then all is good for another 10min of driving. The truck runs great other than the reduced engine power.No smoke, all temps are in the middle,the boost dosent jump up or down,no noises. Only thing that i can see that is not correct is the oil level is a bit high on the stick. Any help would be great.