Removed and deburred the F601J left and right angles. Marked the centerlines of the holes for mounting the F-601TD. Transferred marks to the face for alignment. Held the part with duct tape and drilled #30 pilot holes for the pass through holes and cleco'd in place. Match drilled through the firewall, then used a step drill to open the holes for the line fittings. Deburred all holes. Started on fitting the firewal recess.