After many delays, I pulled my 292 based engine to paint frame and do a front end rebuild.  Getting engine back in frame and running, and time to refill the coolant.  Block has antifreeze from running before. Theres no heater hoses yet.  I was wondering if there is way to fill the radiator, and system , so as to avoid an airlock, other than elevating the motor higher than the rear.  Thermostat is in place.  Radiator is a an Aluminum Champion 3 row with sacrificial anode.  Plan on filling slowly to avoid bubbles.  Any other precautions I should take?  All thoughts appreciated.