AC delco R45TS spark plugs are correct for my truck. the local hillbilly Advanced auto sold me Autolite 685 plugs and told me the same thing. after comparing them to the correct ones that are in the truck now, my new autolites look a little different (the threads go further and the ceramic part is shorter). So how do I correctly cross reference them? Will the new autolites work in my truck, or do I need to go back to town and swap them in on the AD delco's that I know are correct?