Hi ... thanks for that ... Have filled block with water and left it ,,, no water loss, so I'm guessing block is OK, Am taking the head to Slark engineering tomorrow for them to give it the once over and make sure thats O.K. ...If so I'll getr a good head gasket and reassemble the thing and put an appropriate flushing stuff through it to clean it out...
Let you know how I get on.
Phil