The 2012 GMC Sierra 3500 HD 2wd Dually bolt pattern is 8-210 mm. This means there are 8 lugs and the diameter of the circle that the lugs make up measures 210 mm or 8.27 inches across. To get a close measurement of your 8 lug bolt pattern without a bolt pattern tool you should measure from the center of one lug to the center of the lug across from it.
