You replaced the thermostat in your 2001 Chevy venture but the van is still overheating the top radiator hose is hard and hot to the touch like the thermostat is not opening up please advise?

The top radiator hose is above the thermostat. If the top radiator hose is hot, the thermostat is opening. The thermostat is not the problem. Perhaps the radiator is clogged up or the water pump is bad. Look elsewhere.