Id go to the closest dollar store and get the non-fuming oven cleaner and soak it down real good, then hose it off. You will be amazed what that stuff can do when its left on the block for an hour or two!! That will loosen up all the loose grim from the block and the hot tank will be more effective. Make notes and pull every plug you can in the block, aslo cam bearings! I worked at a local machiene shop in college and that was my job, tear down and cleaning before anything touched our shop.