Quote Originally Posted by SuperST8 View Post
If you have that much rust you would need to clean the water passages with bushes and remove core plugs [freeze plug wrong term.] to remove sludge. Best done with motor out of car. Some have put a filter-strainer in radiator hose to preventing plugging of heater and radiator.

thanx superST8, I couldnt recall them core plugs, freeze plugs is from my antique memory bank. Also I should have mentioned to disconnect all hoses,and fixtures from block then blow out when engine is real dry lotta dust in there, [wear dust mask].