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?

No difference that I know of.  Subaru may simply have superceded the part number which happens all the time.

 

Emily

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If the dealer stated the 11044AA770 SUPERSEDED than that 'appears' to be wrong, and the link above shows why (ports don't match).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 June 25, 201510 yr by wtdash

thanks for the response.. ill check them out and see if "the ports" match up

the 642 HG are $5 cheaper too.

 I have a 98 loyal outback and would like to put a newer 2.5 turbo into it. I am a certified mechanic but I would like to know if anyone has tried it?

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.