RE: WACO YMF
The entire black air horn wouldn't fit without cutting the cowl, so I trimmed it back, but left enough to help smooth airflow into the carb throat. It's always hard to tell what kind of eddys and swirls the air inside the cowl is doing, just wanted to make sure the engine gets as smooth an intake flow as possible. The screws that held the carb to the engine were also too long without the horn in place, and I chose to shorten the horn, instead of cutting the screws back.