You will need to make two modifications to the upper air box, closing off the original air outlet horn, and fabricating and mounting a new air outlet horn.
Now we will do the work required to seal the original air outlet horn hole. Get your Can-O-Scent air freshener and a plastic bag. Open the Can-O-Scent and remove the three sponges, which are swimming in really strong stinky stuff. Put them in the plastic bag and seal it to try to control the smell. Wash the aluminum Can-O-Scent Can and remove the label from the side. If you care to, now is a good time to paint the bottom of the can. (I did mine in black Hammerite.)
Coat the entire side of the aluminum can with the black RTV and then push the can into the original air outlet horn hole from inside the air box. Get it all the way in there. A lip on the bottom of the aluminum can will stop your progress when it is all the way in.
Drill two 1/8-inch holes through the sides of the old air horn and the aluminum can. Put two rivets through these holes to provide the necessary mechanical connection to hold this block-off plate in place.
Using more RTV seal the inner and outer edges of the air box and the aluminum can, which is now the block-off plate. Also dab the two rivets with RTV.
Note: I plan to put an air tap (Fitting) in this block-off can to provide a source of filtered air for intake to my York compressor when I install it.
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