I am looking for a service manual for my 1968 GMC 9500. On Ebay, I find regular service manuals for that year and model and also service manual supplements for that year and model. My question - do the supplements have additional information that the regular service manual doesn't have for that year? Or - do the supplements add new information to the previous year's service manual? Do I need to get both the regular manual and the supplement?
Last edited by Memphisdoug; 07/24/2018 9:20 PM.
