New cooling system, still overheating.

•When does it get hot? On the highway or at idle?
•What is the actual temperature?
•Are you sure your cap is good?
•Does your lower hose have a spring in it to keep it from collapsing and restricting flow?
•Did you verify that your new thermostat is good by tossing it in a pan of water, heating the pan of water and noting the temp when the thermostat opens (this is almost mandatory with todays crappy replacement parts).
•Are you running coolant or straight water?