Are the upper baffles between the core support and filler panel in place, along with the lower baffle panel?
Your total timing is 32, but what is your timing at around 2500-3000 rpm with the vacuum advance hooked up? Make sure the vacuum advance can is pulling at higher speeds. Should be drawing 40-50 degrees of timing at highway speeds with the vacuum advance hooked up. Of course, run full vacuum, not ported.
Not sure about straight anti-freeze, they always recommend a 50/50 blend. I would drain half of your radiator and replace it with water, that will give you a 50/50 mix.
As for trapped air, you can take out the thermostat and drill a small 1/8 hole in the ring. That eliminates hose collapse and air pockets. Some new aftermarket thermostats have this feature now.
Remove the electric fan, and use a stock 18" clutch fan. The fan tips should sit about 3/4 into the shroud. Not sure why people remove their factory setups. They worked when the car was new, they worked under GM warranties, they worked on millions of cars GM sold, yet people chuck it and go with an electric only.
