I am building a EJ257 for my Euro GT98 , what heads are better for this block?.

- Euro 98 Heads (211 hp)
- JDM WRX 95-96 (260 hp)
- JDM STI V2 96 (275 hp)

I know that the best ones are the STI V3-V4 but they are very difficult to find.

 

the 95~96WRX are the worse of the three.

The UK98 have good cams but only hydraulic tappets..

the Sti2 have solid lifters etc.. so can rev but not 100% sure how wild the cams are compared to the UK98 which I know are reasonable.

I would probably plumb for Sti2 given that choice.

The alternative - depending on how much work you are willing to do / have done.. go for phase 2 heads whcih are easier to come by and get an inlet manifold altered to fit..

Simon

 

Assuming that the EJ257 won't be going past 7.5k rpm I don't think there will be much gained/lost between the UK98 and STI2 heads.

Whichever option is available 1st IMO

 

I'm sorry to disagree my friend but UK98 are overbucket shimmed, not hydraulic.

If in good nick seem to rev to 7400 OK on a 2.0, but that's not probably required for a 2.5

Andrew...

 

talking about heads and 2.5's

is there any issue using 2 litre heads on a 2.5 with regards gaskets and compression ratios

is it best to get the chambers altered

 

Simon, as Andrew pointed out the MY97/8 UK heads are solid overbucket shims, and the regular Sti 2's are hydraulic as well...however the Sti 2 RA has solid top hat underbucket shims...and rubbish cams...

If it must be phase 1, and you can't find a set of Sti 2 RA, or Sti 3/4 heads then stick with the UK ones...or get them ported and flowed and do what ever you like

As for Chambers, ideally you want to relieve the edges a bit or better still open them out to suit the larger bore...

 

I thought the uk 98 was the same cast and flow as the sti 3 just different running gear.

 

as usual with Subaru that doesn't match what I have seen of late.

I agree though the 98uk seem a good bet.

lol

Simon

 

yes they are.. I have UK98 head casings with STi3 running gear and custom solid valves.

Simon

 

How good are jdm V7 sti heads on a 2.5 ?????

 

I thought that's what you had Alan?

 

from better to worse:

STI v3/4 -> STI RA v2 -> UK97/98 -> STI v2 -> WRX 95/96

is correct

 

sti2 are hydraulic heads as standard in case this hasn't been mentioned

 

Nobody has mentioned WRX97/98 heads

 

Yes it is , Just seeing if I can better them , And what sort of gains if any ,

 

Allan

did you change much with your heads

 

No its a V 7 jdm STI , with a 2.5 upgraded engine,