Hy Biermann,
3942407811
3 = 1953
9424 = GMC pickup delivery, 5800lbs. g.v.w. 125 1/4" wheelbase
07811 = regular production number
8943404993
8 = 1948 or 58, if the two trucks look alike then it is a 1948
9434 = GMC pickup delivery, 8800 lbs. g.v.w. 137" wheelbase
04993 = regular production number
both trucks would be considered 3/4 tons both would be six volt negative ground. being Canadian GMCs they ar probably powered by Chevrolet engines the 48 by a babbitt bearinged 216 and the 53 by a 235 which may be a precision bearinged engine, hope that helps.
