Best headers for 360 in a valiant

The true solution to this problem would be if header manufacturers would start making A body fenderwell headers again, but that would require frame rail bracing as inner fender aprons are structural components.
True, but the big problem (other than the structural issue you mentioned) is that fenderwell headers can really limit your front tire size and turning radius- fine on a drag car but can be a real pain on the street.
But if fenderwells are really what you decide you want, call up Jardine and he should be able to whip you up a set.