Free air intake
This is an ol trick that has been created by fellow stang owners and f-150 owners. What you do is disassemble the air box. Take a 3/8" drill bit, of course when you do this remove the air filter as well, and drill as many holes as possible. This should create a " swiss cheese" effect in your box. Put everything back together and whalla! Free intake. You just increased your air flow to about 85% and it has been dyno proven to work. My buddy did it in his stang and got about 12 hp to the wheels!!!! He also added the K&N air filter as well and it definitely helped him out.