Modellbeteckningar

The label number itself, I believe it's just a random number Chevrolet picked ...
(Someone correct me if I’m wrong)

For Chevrolet’s pickup truck line in the ‘70s and ‘80s they were as follows:

10 = ½ ton

20 = ¾ ton

30 = 1 ton

Toward the end of the ‘80s – early ‘90s they changed:

1500 = ½ ton

2500 = ¾ ton

3500 = 1 ton

The basic meaning behind the ½ ton, ¾ ton and 1 ton trucks designations lets you know how heavy-duty the trucks are.
Naturally, a ¾ ton truck can tow/haul more than a ½ ton. Likewise a 1 ton truck can tow/haul more than a ¾ ton.