Welcome 52_Ton. Not sure how far you are from me, I'm about 75 miles NE of the big smoke. Do you know what engine is in it? The light duty Canadian GMC trucks had Chevrolet engines, likely a 235.
As you tear it down, you would be well advised to document everything, photographs are very helpful down the road as you re-assemble it.
Be sure to ask if you run stuck.
Leo
