23-11-2021, 07:35 PM
Jon, if you have a good probe around you can get a rod through the side water manifold between bore 3 and 4 up through and into the water passage Tony mentions. It is really difficult to describe the shape of the water passages in this area and a picture and would help you enormously. Have you used a rust removal chemical in the water jacket, this will help to dislodge and dissolve crud in there.
Black Art Enthusiast