So far I have used a gel based engine cleaner. A campbell hasfield cleaning gun.
Update: Dec 29th
More cold weather. I cleanded the block cover/pan in the sink and finished off with qtips.
More ultra sonic cleaning in the house today. On the left you see the head about to go into the cleaner.
While hand washing the bock in the kitchen sink I tried Cheer laundry detergent. I had recalled the speed shop telling me they used Tide block washer. It worked better then the dawn when faced with large amounts of grease and oil.