My truck is a 2014 Sierra 1500 and currently has 20k miles on it. I didn't know there was a tsb for frame rust until now. The coating on the frame is peeling and coming off in pieces and there is a lot of rust showing . Is it too late to get it fixed and recoated by the dealer? Also I have a 6 in lift kit on it, will that add to the price of getting it fixed? As always all replies are greatly appreciated. Thank you