Re: New GMC with 19.5's
 

Actually, GM used to make a Silverado/Sierra 1500HD, and a 2500, all on the same "1500" frame, same frame as a Suburban/Avalanche/Yukon XL 2500.

The 2500HD was used to designate the 2500 Chassis, heavier duty, as well as the 3500HD, but recently they dropped the HD moniker on the 1-ton, SRW or DRW. The 3/4 ton still has the HD moniker. Its just "3500" as far as either GM make, Chevy or GMC.