Almost correct. I wouldn't call them headers though. They do have the flow capacity of shorties though, but not the sound.
Ford finally looked at all the aftermarket add ons when developing our cars. They have a bigger intake and exhaust compared to earlier years.
I believe short headers make more power down low, and long tubes make more power up high. As stated above, the stock headers flow the same as short headers and are not worth the money.
shorties will make a little more than stock across the board. But if you are doing headers it isn't worth the trouble to install shorties, long tubes are going to get you the best gains with the largest area under the power curve. Mid lengths (bassani is the biggest company with this type) are similar to long tubes in gains.