When I first got my 54 3100 in June of 76, my Dad built me some bed rails out of white pine, which he stained and coated with a good polyurethane (I think that's what it was). My truck was outside all the time and the bedrails lasted about 15 years. Whatever you choose to make them out of, just coat it with something durable.
Samantha


1954 Chevy 3100
Picked from the Field
Follow in the DITY