I tried an expandable freeze out plug once and never again. It held for awhile but once it ran under pressure for a short time "pop" and out it came, along w/all my new 50/50 anti freeze. Wrestled a new steel plug back in and to my knowledge it's still holding.
Can't help on the headers, good luck.
Dave
Last edited by Volfandt; 06/24/2013 7:27 AM.
