They are listed in order of size of vehicle. The above is transcribed directly from the parts manual, so anything else is conjecture. But here goes. The top pair of lines should probably have 1000 after each of them to annotate a 1/2 ton truck. The next 2 pairs show 1500 and 2500 to denote 3/4T and 1 ton respectively. That would be the GMC nomenclature starting in 1960 for the weight ratings.
So the short answer to your question would be that the GMC 3/4 ton bars are not the same as the GMC 1/2 ton bars.
I take it that the Chevy and GMC p/n's are not the same? They rarely are.
Last edited by k10; 05/06/2011 3:31 AM.
