I don't know about GM parts supplying manuals for free, but you can see your owner's manual on mygmc.com. Scroll down to the bottom of the page, there is an owner's section. Select the manuals option. It will take you to a page where you specify which year and model GMC you want to see the owner's manual for. After you select the year and model, it will give you a list of manuals to look at online. If you scroll further down, it gives you the option to purchase a manual. Click that link to order a manual. For me, a printed manual will cost $50.
