First off - Welcome to Stovebolt!

Your vehicle serial number/data plate shows your truck is A GM of Canada built Model 1435.
This
Old GMC Trucks web page gives the info you need to decode the serial number. It's a little fuzzy, but you can still read it enough to confirm what you have.
Give it a read and post a reply with what you figure out using this decode info. Others will be along soon to offer more help and confirmation.
