I would prop cardboard as a backing then mask off with clear plastic sheeting....engine degreaser is your friend and there's virtually no such thing as too much(unless you don't like cleaning up pools of degreaser on your intake, haha). If you're stripping, use the stripper(lacquer thinner) BEFORE the final degreasing, lacquer thinner leaves an oily finish that needs degreased. You then can start prepping to prime by using self-etch primer, finding a primer closer to the color you're going will make for less coats required. This is based on if you're doing it without removing parts. If you remove valve covers and other parts, then you can skip the masking off part mentioned above. Are you going to be running single stud open element? If you're converting, I have an extra single stud conversion kit I'll send ya.