39-47 Dodge trucks fit nicely on Dakota frames up to at least 1999 (or when ever the 97 cab was updated, after that, I don't know how the Dakota frame may have changed). Modern everything, choice of factory drive trains, can still use as a truck if the desire/need arises, pretty much add (or move) the frame body mount ears to the locations needed to bolt the old cab on the new frame.

You may have to shorten (or lengthen, easier to shorten one) the wheel base to match your trucks wheel base, but that pretty easy to do on a Dakota frame. With the standard Dakota wheels, the width is just about perfect. The wheel openings on the 3/4 ton fenders may be a little big, but that can be taken care of as well. Also, the frame under the Dakota box is about 6" higher then what the floor on the 39-47 box floor would be. You can move the box floor on the 39-47 higher, but it will reduce the inside height of the older box on the inside of the box. Gene