One problem related to door hinge has been reported for the 1999 GMC Sierra 3500. The most recently reported issues are listed below.
My 1999 GMC Sierra 3500 crew cab was ordered new. I discovered later that it was fitted with a 1998 cab. The design is different and the front doors are longer and heavier resulting in premature hinge failures. I also discovered that it was not equipped with airbags because the 1998 version didn't require them even though I ordered a 1999 which does. I have a VIN on the dashboard showing it as a 1999 and one on the door showing it as a 1998. I just found out about reporting it here.