And who currently builds GM medium duty trucks (4 and 5 series)? Not GM, Navistar/IH builds them for GM. They're built right here in Springfield Ohio. Those medium duty trucks are both, chevy and GMC, the emblems/nameplates are the only difference.
Since post mid 60s chevy and GMC trucks have been sharing most all of the same parts. The last major difference between chevy and GMC trucks was the mid 60s, the chevy used for the most part the independent rear coil spring truck arm suspension in most models, GMC kept using conventional leaf springs in the rear. It is noted that you could special order a chevy in those years with leaf springs, or order a GMC with the coil spring/trailing arm suspension.
The chevy stayed with their 235 inline six, then in 63 they offered their newer design straight six, offered in 230, 250 and 292 Cu In. The GMC standard 6 was the 305 V6. After 1966 they started using the chevy powerplants in the GMC trucks. Starting in 1967 is when GMC and chevy became homogenized into virtually the same truck. As the years went on the two brands became virtually the same trucks built on the same line, with the same parts, save for emblems, and interiors.
By 2009 they could have easily dumped either GMC, or chevy trucks, and stopped duplicating the same vehicle as they used the excuse that Pontiac was a duplication of other GM brands vying for the same customer. The difference is GMC customers will pay a premium price for virtually nothing, other than the myth that GMC uses better quality parts than chevy does.
Like saying a chevy/olds/Pontiac/buick brake rotor isn't the same quality if you buy the same part # at a chevy dealer, you rotor is substandard to the same rotor bought at a buick dealer.............
You have all heard the slogan on TV, "GMC trucks, professional grade". It's a crock of crap that is kept alive by the GMC sales/PR people, and has been for decades.
