Running Hot on the Highway

For sure the first thing I would do is ditch the 160 stat for a 180. also if your lower hose is sucking shut then you know you have a flow problem. the hose sucking shut tells you the pump is pushing the volume of coolant passed the stat, through the radiator but the radiator can't supply it back fast enough so it builds pressure in the upper hose and sucks shut the lower. In alot of cases the high flow stats are not necessary and can prove to be more of a problem.