When I do a rebuild, I generally just fill the system with water until I get all of the bubbles out and I'm sure there system is functioning properly. That way when it does start puking out, you're not getting that sticky antifreeze all over your fresh clean engine. Once I'm sure it's functioning properly, I drain just enough of the water out to add the appropriate amount of coolant to the system. Also, pulling the coolant line off of your EGR spacer will be a good way to ensure the water is getting all the way through your system and the air makes it way out. But then of course...you might not want to do that if you've already got it full of antifreeze. Not unless you've got a good size bucket on standby.