Originally Posted by Habanero

Having the valve cover off wouldn't allow you to see any cracks unless it is tremendously catastrophic. The cracks are on the combustion chamber side. I am not real sure about the pressure test as a check, either. Mine would hold pressure in the system for days, that is why the upper radiator hose is hard when cold, it is holding pressure. I think the truly best test is checking for combustion gases in the cooling system, but the circumstantial evidence is usually enough to prove the problem.