gross? how about grossly functional?
I used ply in my 57's step bed, cuz it wasn't worth spending much money on and it needs to earn it's keep, and I live in
the rain forest of the PNW - the plywood, painted top, bottom, and all edges, will last as long as boards, even when there's frequently standing water in the bed
mine is going on 5 years now and other than some spots worn thru the top marine enamel, is still fine - all depends what ya wnat the truck for, if it's a driver plywood works fine, if it's a show truck "restoration", well, plywood can still work
Bill
