if ya wanna have a properly "restored" truck, yellow pine is what's correct, and properly coated it'll last decades - if ya wanna have a glossy trailer queen, use whatever turns yer crank, it won't get used or abused so "holding up" isn't an issue - if ya wanna have a good ol work truck, use what's cheap and sturdy ... around here that's Douglas Fir, and I expect the fir floors in my truck beds will take getting worked hard and put away wet for longer than I'll be alive and last as well or better than the sheet metal, just like the pine did first time around!
Bill
