Cooling System Refill (Late B)

[Eugene Balinski <eugeneb@nni.com>]

I am about to replace the thermostat in my 80 B.
I am wondering about the correct method for refilling 
the cooling system since the radiator does not have
a direct fill neck.  The filling is done by either in the
overflow tank, or via fill port above the thermostat
on the engine block.   I am concerned that the 
radiator and block may not fill completely of that I may trap 
air in the system.  Do I need to be concerned ??  Any
hints ??

Thanks,
Gene 
80 ' B