http://www.jscspeed.com/part_pictures/gpmoto_header.jpg

Full stainless steel, one-piece manifold that is semi equal length. It doesn't get much better than this. This header also features a very straightforward install -- the engine does not have to be removed/raised for installation. We're using this header on our project STi. This is also a great way to eliminate leaks, as it attaches to the block and to the turbo, that's it!

As a side note: this header does not cause the WRX or STi to sound like a Civic, regardless of what your local autoparts guy might have told you.

This is a great header, currently available for a great price, PM, call or email chris@jscspeed.com for details.

Any dyno result gain from these on a ej205?

To be honest I haven't seen anyone dyno one on an EJ205, without a pile of other mods -- probably because a header isn't really a typical first mod. Just taking the OEM catted uppipe out of the system is going to free up a whole lot of power, however, so you will see gains.