Hi Kevin I anguished over the same thing as tube frames rust from the inside out. You need to drill holes for fuel and brake lines to secure them. The 427 utilizes the same holes for two fuel lines and the brake line to keep them all to a minimum. They also use the frame extension holes to thread them through. On the other side it has a battery cable also requiring holes and clips. Mreid's suggestion is a good one. I'd also consider some used engine
oil or there are various rust treatments available you could put in the holes to treat the inside.