Just use a stack of fender washers between the flap and the crossmember- - - - -5 or 6 of them will space it back 1/2" or so. A couple of strips of 1" wide aluminum flat bar 1/4" thick would do the same thing. Why is common sense so uncommon these days?
Jerry
Not that uncommon, Jerry. My original question, if you'll recall, was HOW FAR back was far enough? If 1/2" is all I need, no problem! If I need more, then I'll come up with plan B.
This truck isn't going to be used that much. The flaps are mostly for aesthetics.