I drilled and tapped the 3/8” bar for ¼”x20 tpi all thread with the spacing matching the original holes in the deck lid front flange. Had to ream the holes in the fiberglass our about 1/32”. Added a 7/16”x7/8”x28” thin steel (approx. 24 ga.) rectangular tube spacer behind a 3/8”x1”x 43” long aluminum bar to attach the hinge to. Had to put individual shims at each end of the 3/8” aluminum bar as the deck lid curves in to keep the hinge mounting surface straight.