Hey Guys, 
   I am about to start a yblock that has had its cooling system and block drained, and now needs refilling with 50/50 antifreeze.  I have read that removing the thermostat, and filling through upper hose will help with not getting air bubbles in the system.  After good circulation, drain enough to install the thermostat, and refill.  Is this correct?  If so, do you just put a certain amount in that hose and fill the radiator, or can you fill entire system(roughly) through upper hose.  This is a stock 57 yblock system, running in just a stand     Can I just fill radiator with thermostat in and run engine, checking flow and bubbles?  Looking to avoid cavitation or hot spots from air bubbles.  If anyone has looked into this, findings would be appreciated.