Red,
POR = Paint Over Rust. Using POR over a rust free part is a complete and utter waste of time and money.
Do you plan to drive your truck in rain and snow? Are you planning a show truck? If the answer to either of these questions is no why not just save yourself all this expense and work and just paint your frame with enamel? Get a couple quarts of Rustolium or Valspar enamel, thin it to manufacturers specs and spray or brush it on.
Yea, yea I know it sounds so hopelessly old-fashion but it works. You'll have a perfectly rust resistant frame with a coat or two of durable, proven paint that will last long after you sell it.
