Anytime I do coolant work on a vehicle without an air bleeder built into the system I do the following, always works.
Remove the thermostat housing and thermostat, as well as the radiator cap. Fill coolant resevoir halfway in between hot and cold lines. Fill the engine through the themrostat hole until just about full. Then top off the thermostat hole by slowly pouring coolant into the radiator. This eliminates air in the engine. Reinstall thermostat and housing, then fill radiator. Leave radiator cap off and start engine, turn heat onto high. Coolant level will likely drop, so keep it full. Idle the engine for about 5 minutes then reinstall the radiator cap, engine still running. Sit in the drivers seat and if the gauge gets above your normal running temp, rev the engine to 1500-2000 RPM and hold it for about 5 seconds. This pushes coolant up to the thermostat if more air has made its way into the engine. Watch the gauge until you see the thermostat open, revving about every 20 seconds, the gauge will drop about 30 degrees or so during a cold start. When the gauge drops rev the engine engine. Let it idle about a minute more, then shut off the engine. Wait a few minutes and remove the radiator cap, careful it will be hot and under pressure, do it slowly. Top off coolant if needed. If it seems like you are adding an awful lot of coolant at this point, you may need to repeat the 'engine running, rev, watch gauge' thing again.
It sounds like a lot to do, but its quite simple and the 20 or so minutes of doing this keeps you from having problems later.
Keep us updated.