I was confused also, I thought it would have a Dana 44, like my original 1960 GMC and many GMC's. Does not really matter. If it's Canadian, could have used different diff than USA? (Canadian bearings found and he lives in Canada) "C" 1000.
Steve: It depends on how pitted the shaft is. You could actually ruin the fit by sanding on it, until you reconnoiter the situation. Move cautiously. I don't know anything about repair bearings except it sounds like something I would not want to do.
Don't worry about brand of bearings, even the biggest names are made in China. Just buy a bearing from an auto parts place.
Pitting does not automatically mean it can't be reused. However, at
$130, it's better to buy new than to spend anything on them or special bearings.
Check around for pricing. Be sure you know your dimensions and spline count