Shouldn't be much more than an afternoon's worth of assache I figure. Remove PF entirely, move rear mounting points down several inches, mount a lower front bracket or fab up longer hooks to grab the original bracket. I know on most of the 70s and 80s pins I've had there is room to drop it down, never tried anything like that tho. Might run into other issues, button placement, wiring extensions to go from PF to back box etc.