Yup...they most all are messed up
Take my 1996 K3500 Suburban. Tongue'n cheek call it a K3500 'cuz ordered it with
the snow plow prep, option #F60 and begets 1 ton front torsion bars/etc
OEM FGAWR is 4,250 and stayed the same with the F60 option. OEM 1 ton dually
has a FGAWR of 5,400 IIRC.
OEM RGAWR is 6,000 and is the same rating as the 1 ton dually of that year. AAM
rates that 10.5" diff assembly 10,000 GAWR
So should I take the OEM 8,600 GVWR to become 5,400 + 6,000 = 11,400 GVWR ???
Or take 5,400 + 10,000 = 15,400 GVWR ???
Then gotta change tires and wheels from LT class to commercial class
Then what about the brakes and a huge etc, etc, etc
Ratings are a system with weak links...but we on the outside of the design
team will NEVER know which one(s) it is...