Shouldn't be overheating, unless the temp sensor is faulty...takes forever to show 180°F on the gauge...like 10-15 minutes...is that normal ?
"Pressure test" meaning a cylinder compression test ?
I actually finished correctly timing this engine today... Initial is 12° BTDC and the balancer mark is hitting the 0° on the timing tab... Total timing is 36° @ 2500 rpm...and when I checked initial timing after setting total timing, the balancer mark still hits 0°... I'm assuming timing is finally correct.
The smoke doesn't smell sweet...like coolant.
It could also be a small bit of air in the coolant as well.
My advice, replace the thermostat, gasket and rad cap man. Then run the Monte for 30 minutes with the heat on max, while the rad cap off for the time. Rev the engine to 2500 RPM every few minutes, and then squeeze the upper hose a few times- you will see some bubbles but will become less obvious.
Add coolant as necessary, and then put the radiator cap on. Shut the car off then, and check the coolant levels in the reserve tank in the morning.