Overheating

I have the vehicle listed above and it ran really good, my wife was driving it one day (we use it as a spare car) to pick up the kids, and it starting to overheat. She stopped, pulled over waited for it to cool down, she eventually made it home. I looked and it was leaking coolant. I though it was the water pump, so I replaced it. Started it up and it had a leak still. I found that the throttle body heater hose was cracked and leaking. Replaced it. Took the vehicle out for a test drive, it overheated. Long story short, I replaced the thermostat, coolant reservoir, radiator, fan clutch, hoses, water pump. I do not know what to do now. It does not necessarily overheat in idle, it overheats driving over 30 mph. I checked the oil, no water or coolant, and no power loss and no white exhaust. When I refilled the coolant it took a little over three gallons. I am running out of ideas. Help please!