So I finally got my rebuild done, engine is in, everything is connected and looking beautiful!
I fill the radiator up with water for the break in and it starts pouring out of the side of the block...after a mild heart attack I realized the coolant plug was missing from the block. It was in when I took it to be boiled out and just overlooked making sure it was there when I got the block back.
Long story long...what do I need to put in there, I can't find the proper plug on line dang it!