Edelbrock Head Issue - Anyone else have this problem?
My guess during the casting process there was a weak spot in the aluminum maybe pocket of bubbles or slag: contaminates that collected in that spot and was weak and with the heating up and cooling with the antifreeze it ate away or broke apart the weak spot? Grind it out to clean up the hole inside and out and have a welding shop aluminum weld it up and then file , grind and or sand it smooth. I had to do that on an edelbrock performer intake where the coolant flows and to seal up the heat cross over port hope this helps? Yes also use that zink anode rode 2-3"'s long for inside the radiator to counter act the chemical reaction between the coolant and the aluminum. You can buy one in the speed catalogs jegs ,summit