Tim, in the link you gave in an earlier post the brocure for the 56 model year has some things that make me scratch my head. 12 volt was standard for the 56 year as was something called "kudu stabilizers" in the engine bay. My truck was 6 volt when I got it and it does have the kudu stabilizers. If you are correct with the engine code dating, that was way late in 55. Did the new models come out after the first of the year back then or did they do it like now with new models coming out in late fall? I was born in 56 which is one of the reasons I've held on to this beast as long as I have so I don't have a clue as to when the model switch happened. Could it be that this was a late run truck that didn't hit a show room till early 56 and still had the "y" code body, but still had several of the 55 parts along with some of the new stuff for the 56 models. And was the 18991 in the serial number the number the truck was off the line? If so how many turcks did gmc produce in a typical year back then?
