A major change in large truck Chevrolet front bumpers occurred during there years. Prior to 1946 the 1 1/2 ton bumpers and braces were little more that a heavier guage design of the smaller 1/2 ton.
The big bumper change was in 1946. (Possibly this was because Chevrolet introduced its first 2 ton model that year.) Now it was nothing like those on the 1/2 and 3/4 ton.
This new heavier, stronger bumper design continues on GM’s larger trucks to this day.
1941 Front Bumper (above)
1946 Front Bumper (above)