after some measurements I made a couple of jigs to properly position my mounts using the HFD . Marked and cut out the squares. Used some scrap 1/8 ply taped to the fire wall to set the depth of the mount on the forward side . When I made my mounts I purposley drilled the holes under at 1/4 inch . After locating the position , using a drill block I pilot drilled the mounts thru at 1/4 inch.
