I have a JDM EJ20 DOHC engine of unknown origin. (ie. I have not been able to identify which model 2.0 it is). Is has a stock block, heads and turbo, but everything else (i.e. intake, exhaust, ecu, wiring, etc are all custom).

Engine I.D. clues:
* old style 2-piece hydraulic timing belt tensioner.
* Coils on plugs, 2 bolt holes on coils

Here is my question: Are all 2.0 DOHC heads good for making a EJ257 hybrid? I have read of many people doing this with 2.0 WRX heads. Not knowing how many versions of 2.0 DOHC heads there might be, I am wondering if there is any difference between my JDM 2.0 heads and the newer 2.0 WRX heads? Are there any 2.0 DOHC engines that were non-turbo (normally aspirated)?

I currently have rod knock on my motor, and I am looking into repairing it vs. doing and EJ257 shortblock transplant.

FWIW - After the EJ257 shortblock I wont have lot of extra $$$ available at the moment for a new turbo, waste gate, injectors, rails, etc, so those upgrades would have to come down the road.

Thanks.