Are all of the EJ25 short blocks interchangeable? For instance, would the short block from a Phase2 SOHC ej25 or the ej25T from an 04+ STi or forrester be a direct replacement for the Phase I DOHC ej25 in a 96-99 Legacy?

 

They are all bolt-interchangeable, meaning that they should bolt in. The problem comes when you get to compression ratio. The turbo blocks will be much lower than what the engine needs, so replacement pistons are required in order to make the swap work. It would be best to find a SOHC long block and rid yourself of all DOHC moving parts.

 

Thanks, it's just the mount points that matter to me, I've still got to decide whether to go turbo or not, which is why I was asking about both.