anode for heat exchanger

[Mate Matthew]

Hi, I just purchased a 1979 17ft caravelle with a 470 in it. I am replacing the head gasket, since the oil pan was full of antifreeze, and was going to check and clean the heat exchanger while I'm at it. My question is, dose the heat exchanger need a magnesium anode in it, and if so where might I find one. I am only using the boat in fresh water. any advice and help would be greatly appreciated. would also like to know what oil others are using in this engine and in there lower unit. thanks

 

[Scott Danforth]

Been a while since I worked on a 470 .dont remember if there is a zinc or not. Look for a 3/8 hex pipe plug. Would be on one of the ends. The zinc pencils are available nearly anywhere. I get mine on amazon