I don’t have access to a powerwasher without renting a trailer nor do I have access to a hose connection, so I purchased a steam cleaner and went to town on the engine bay. Use nylon brushes, simple green, and the steam cleaner. Turned out really nice and clean. Next step is removing the old adhesive from the sound pad, and then repeating the process for cleaning the bottom of the tub.
Also I’m still looking for a decent powder coater who doesn’t mind low volume and doesn’t charge a minimum for satin black in the north Texas area.