rd, If your truck is a 350 series, you've got a 2 Ton, 16000lb.gvw truck. GMC's 1 1/2 Ton truck during that era was a 300 series, 14000lb.gvw. As far as the aux. trans. is concerned, a good way to tell if it is factory, or added on later, is to look at the workmanship of the way it's installed.
