The motor is stock and tune is stock for now I did have some problems it was getting warm climbing some good grades i am pulling about 12,000 lbs I dont know if i have air in system? I shouldnt i blead it 3 times,The radiator never gave a problem with other engine,Temp did climb a bit under some hills.I am thinking a bad cat or air myself it has a new w/pump,T-stas (GM) and new coolant IDK what the heck it is though i dont want to get her hot and i need to get this figured out any ideas guys i am baffled