I did not realize what was involved in the FAB construction. The box needs to be fit to the type of engine you have in your plane. I have a Bendix fuel injection servo and it is off set a good bit from center of the plane. The engine air intake scoop on the bottom cowl is in the center. So the inlet of the air box has to mate up with the scoop. I had to make a new engine mount plate with a greater off set to start. Then mount to engine and put cowl on to get inlet centered on intake. Once all is aligned the fiberglass box can be riveted to the top plate which has had the filter tabs mounted. Next the box is mounted to the engine and the intake on the cowl will need glass work to extend to almost touch the inlet of the box.