I was not going to get pulled into this, but for the record I would love to hear from someone who works the parts counter at a Ford, Dodge, or Chevy Dealership.
I do know there is a BIG difference between my 2008 2500HD and the 3500HD. While the engine, trans, and rear end ratio are the same (thus the tow rating is the same), the frame is completely different.
My 2500HD has a C frame and the 3500HD has a box frame which results in the very different GVWRs.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW