few quesitons about this. can i use the 2.5l dohc heads on a wrx block? it is a built block and will be built heads. will the top of the combustion chamber look like a mushroom? also will the wrx intake manifold bolt onto the 2.5l heads.

The heads will fit the block, but the ej205 wrx intake manifold won't fit the heads.

Chamber diameter is too large for a good HG seal on a 92mm bore.

Chamber diameter is too large for a good HG seal on a 92mm bore.

I was afraid someone was gonna say that. This is TRUE if you're using a '96 EJ25D head. This is NOT true if you use a '97-99 EJ25D head.

This is assuming he's talking USDM.

usuing a very early 99dohc head. how hard would it be to use a 99 dohc intake manifold and make it work in a 02 wrx

usuing a very early 99dohc head. how hard would it be to use a 99 dohc intake manifold and make it work in a 02 wrx

The IAC is totally different. That is the biggest issue.

I was afraid someone was gonna say that. This is TRUE if you're using a '96 EJ25D head. This is NOT true if you use a '97-99 EJ25D head.

This is assuming he's talking USDM.

91.6mm chamber diameter is a but much for my taste, lots of block deck shrouding valves.

91.6mm chamber diameter is a but much for my taste, lots of block deck shrouding valves.

This EJ20G head (2.0L) is the SAME CLOVER style as our USDM 97-99 DOHC EJ25D.
http://i248.photobucket.com/albums/gg176/ej22tim/122.jpg

here are the USDM '96 DOHC heads. The combustion chamber matches the bore of the 2.5L
http://i18.photobucket.com/albums/b121/FuJi_K/Head%20ports/IMG_5005.jpg

Nice one Fuji, didn't know that about the HLA EJ25D heads (but then again, we didn't get those in Europe :p).