On the AD's one serial number plate located here DS door jamb.
https://www.flickr.com/photos/advance-design_parts_co/8130531991/in/set-72157631870734114
One engine number located here. You can see it to left of distributor.
https://www.flickr.com/photos/advance-design_parts_co/8473965333/in/set-72157632770756320
Some states like Utah used to title to both, like this title of mine shows. Now they just use the serial number. There are no frame numbers on AD trucks.
https://www.flickr.com/photos/advance-design_parts_co/12142231614/in/set-72157631870734114