Shown is before and after, stock OEM unmodified head flow numbers vs. Port and Polish, deshroud, +1mm ex. & In. Valves.
Heads where purchased brand new from Subaru and then sent to ASF machine for modifications/flow testing.
1998 ej25d. Parts #: 11063AA762, 11039AB123.
![Image](https://farm5.staticflickr.com/4497/24291431788_47778a37db_z.jpg)
I've been catching alot of flack from people for my interest in the phase 1 heads, but these numbers help to show that the ej25d heads are very much capable of making some big power. While most people's logic is to go for phase 2 big port heads, I've chosen to step away from the norm and see how far I can take the ej25d heads.
I'm extremely happy to finally have flow numbers for these heads, I hope it aids as a comparative data point for the community.