This is my dyno run with the BBK shorty headers on my 2011 3.7 Mustang convertible. The Red and Blue runs are my previous runs with stock headers mid pipe etc. The Green run is the shorty headers, no other changes to the tune were done all running at the time bama 93 Oct tune. You will note between 3.2k rpm and say about 3.8k rpm on all runs a dip in torque/HP we believe the tech was not fully disabling traction control on the runs. (He was hitting the TC button but not holding it to shutdown advanced trac) What you will note there was not a real big gain over all in HP but there was a 10 ft-lb peak gain in torque which really just for a bolt on is ok, what is notable however are the torque and HP gains along the curve especially below 4k RPMs as much as 60ft-lbs around 3000RPM and about 30hp at the same RPM, and the gains continue after that dip from about 3800 to about 5350RPMS.