2.5L Head Gasket Difference

[valheru]

Anybody knows what is the difference betwen these head gaskets:

2.5L DOHC Turbo: 11044AA641 - '03, November — '04, July
2.5L DOHC Turbo: 11044AA642 - '04, July — '06, June
2.5L DOHC Turbo: 11044AA670 - '05, November — '07, March

This is the stock one for my '05 2.5RS:
2.5L SOHC N/A: 11044AA632 - '04, January — '05, May


I am looking for my n/a build, I've been told to get head gaskets for a 2.5L Turbo, but which one?


Also, ss there one of those listed for the 2.5L turbo that is thinner in order to raise the compression or going this route is a not recommended?

Thanks

D.

[Navigator]

Why not get the Cosworth Gaskets? What kind of "build" is it? Stock, higher compression pistons? More info required. ;-)

[valheru]

Stock bottom end for now, with built heads (cams, CC match, mild P&P, seat/valve regrind), intake, Cobb EL header with a metal core HFC and a tune for 91.

Future plans include high comp pistons and supporting components when this one dies on me.

I was told to stick with OE cause you don't need to re-torque them after 1000 km of usage.

[JoeT]

The 2009 STi gaskets are 3 layer MLS with a triangle in the coolant return passages. These will work fine with your engine. But use the 2007 STI gaskets, they are the same as the 2009 as they are 3 layer version, but with the traditional size coolant return holes in between the cylinders.

Both have the upgraded coatings, so no need to worry about HG problems unless you overheat the engine.

[valheru]

JoeT wrote:
The 2009 STi gaskets are 3 layer MLS with a triangle in the coolant return passages. These will work fine with your engine. But use the 2007 STI gaskets, they are the same as the 2009 as they are 3 layer version, but with the traditional size coolant return holes in between the cylinders.

Both have the upgraded coatings, so no need to worry about HG problems unless you overheat the engine.

Just so I don't order the wrong one:

2007 STI = 11044AA670 - '05, November — '07, March

[Navigator]

The dealership should have stock, take the one from your block with you and verify all the holes are identical. I know there were small differences in some head gaskets 07 + I think.

May not be something you want to order online.

[valheru]

Thanks for the info.