Be sure to "fish" around inside the block for "extra" expansion plugs. Back in the 60's I pulled 3 and 4 plugs our of engines because some folks would just drive the plugs on into the block and put the new ones in. Usually it was on cars with other than original engines where space was limited..
...I've heard it said that its better to mix concentrated anti-freeze with distilled water but hey, don't the metal block contaminate the distilled water anyway!!
...after 60 years, or more, just about anything is possible!
Last edited by Achipmunk; 04/16/2016 1:54 AM.