BBC Dart aluminum 325 cc cylinder heads they were marine coated, as you can see things didn’t go so good for me(look close at pictures) The boat they were on was flushed every time and kept on a trailer I believe it to be electrolysis damage,in any event they were used for two seasons the motor did not overheat or have any head gasket problem before taking them off the motor
if somebody wants to mess with them make me a reasonable offer need to move them out of my way call or text 631-786-1647 heads are located on Long Island