You shouldn't have any problem using a pressure wash if you have the valve cover down snug. Just plug any holes you might have in the valve cover and use a towel, can, or rag around the carb. If you still have some old paint left on the block, don't worry about it. The new paint will cover it fine and won't pull away as long as the gloss has been taken off and its super clean. I covered some old paint on my engine and have never had a problem with it. Cecil.........
