Value is a pretty varried topic. It depends a lot on how much rust there is, as well as the area you live in (prices are way lower out here on the west coast) and well, like anything else, how bad someone has to have it. A shortbed will always bring a little extra money. Some guys like the 69-71 less (dash, grill, and hood are a bit different), but it's totally a presonal preferance thing. Cab floors, rocker panels (underneath, too), door bottoms, the front lip of the hood, edge of the cowl, and under the tail-lights (behind the bumper corners) are the typical rust problem areas. Hope everything works out for you on the trade.