I have the in-line 6 in my 2005. Just turned 40,000 miles and I have to replace the rear main seal. The truck is rust free (FLORIDA),however from plowing snow this (the first)winter for this truck the oil pan has bubbling rust starting. Should I replace it or is there something else I can do with it while I have it off? I really don't want to buy another stock OEM oil pan or the same thing will most likely occur next year. This oil pan looked like new in OCTOBER.