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using turbo HG on non turbo 2.5 sohc


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I have a question: when using the 2.5 turbo HG on a non turbo 2.5 sohc engine is there a difference between the two turbo gaskets offered?

I have been using the 11044AA642 but they sold me a set of 11044AA770 which are for the STI engines.  Is there any difference?

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Hi,

Actually there is a difference due to a change in the head design, I believe. See (and view the differences) this LINK on NASIOC.

 

I came across these differences when considering an engine swap, here's what I found:

 

 

  • Head gasket: Note that HEADS should determine HG to match ports B25 vs D25 heads, etc.
  • >>>>>>> All EJ257 STI, models build dates 1/04-6/06 AND EJ255 FXT, OBXT, LGT, Baja Turbo '04-'05 - 11044AA642
  • >>>>>>> EJ255 2.5L WRX and EJ255 FXT, OBXT, LGT, Baja Turbo '06+, AND STI '07+    - 11044AA770

 

If the dealer stated the 11044AA770 SUPERSEDED than that 'appears' to be wrong, and the link above shows why (ports don't match).

 

But I don't know how this affects your SOHC NA application.

Edited by wtdash
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  • 3 weeks later...

I put the 04 sti spec MLS gaskets in an 04 SOHC ej25 I did for a friend and they have been working fine. Didn't seem to be any significant port mismatch when I laid them on the heads. It was the weird CA emissions spec EJ259 though, with the big H6 exhaust port and 4 cats.

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