On the treated wood use..dont. Appox 2 yrs ago the goverment banned the CCA treated lumber we all used for yrs. In its place we now have ACQ treated lumber. This stuff is nasty, and will eat most metal that come in contact with it. Fastening it requires the used of coated or galvanized hardware. It will eat right though a common nail or bolt with a few years. Its causing a lot of trouble in the home building industy because of lack of knowlage by the contactors.
For use on trucks there are now some lumber coming out, using a differnt kind of treatment that doesnt require any special fastener, but its pricey. Another thing one might do for a bed is use cedar or one of the vinyl decking products on the market.
On the frames all our yard trucks use white oak. On trucks with tied down beds we use 5/8" U bolts, made from grade 8 rod stock. Double nuts are also a good idea.
