I've been running LPP's for about a year now and they have lost their polished shiny look. I don't want to say they are rotting away, they have some surface rust where the heat is concentrated on the primaries. They are very nice headers however with extremely thick flanges and excellent build quality. If I could do it again I would've had them ceramic coated for more protection but they are something like 304 stainless (dont quote me on that). So even if they rust some on the surface the are still going to outlive the truck, they just wont be as pretty as they once were. The combination of the Nelson Tune, LPP long tubes, ORY, and my Gibson Extreme Dual setup produces an awesome soundtrack too.

PS - I live south of Buffalo where they salt all the time in the winter so my truck has been exposed to very similar, if not worse, conditions that yours will be.