Greg has it right for many locks but the locks in our old trucks use little flat pins with a hole in each instead of the brass tumblers. They are numbered 1-5, to correspond with the 5 key cuts.

Joe, I have a code book. If you or anyone else wants a code looked up just PM me.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.