Bed wood help

[1972Ryan]

I have a 72 GMC stepper and the PO had put aluminum sheets in the floor of the bed. Wood and strips are long gone. I am wanting to replace the floor, but I want to go a different route. Does anyone have the measurements of the original bed wood boards for a shortwheelbase? I need the widths, lengths, and height of the boards. I want to install that plastic decking boards in its place and still have the metal strips to where everything still looks like the old bed, just with boards that don't rot. I know the widths are different and I think they are all 1 inch in height. If anyone can help me I would really appreciate it. I will try and post pics when I start it if anyone is interested.