Not looking to argue
I try to stay away from the Forums, on an occasion I look at the links back to our site and have a peek. I have no desire to get into any sort of an argument, I only want to try and clarify a few things.
It appears that Subaru did change the cylinder head and or block casting, if you look at the very center portion of the head gasket you will observe there is only one center hole in the gasket for coolant to flow through where as all of the previous Subaru head gaskets for the U.S. production E.J. series there has been 2 holes for Coolant flow.
The cooling jacket ports on the gasket suggest that maybe Subaru has changed the deck as well as they are a different shape and size, but I will know more about this when we take one apart and at that time I will post some pictures on our website. Lastly I want to measure a "crushed" gasket for thickness, as it is pretty thin and could change the combustion temperatures a bit.
Subaru Part # 11044AA633 is not a Multi layer Shim Type gasket. Please go have a look for your self at the make up of the Original gasket. It is a single piece of steel with a gasket material bonded to it. This is the updated gasket used to correct the vehicles that fell under the WWP-99 campaign and is the gasket used in production of all of the N/A 2.5l EJ 2.5l from 2003 until 2007. I am not clear about the part used in the PZEV from 08 to 09 we have not had one apart yet but from the outside it doesn't look like a MLS.
11044AA633 is also the part used by Subaru in the course of head gasket repair at the dealer level for all warranty work and customer pay as well.
I know I have heard there are a few dealers using the same gasket we(which is an MLS) use for non warranty repairs but I don't have any real evidence to back that up only that I have heard that rumor.
Subaru uses an MLS gasket For all other engines aside from the N/A 2.5l. Tribeca, 3.0, 3.6, WRX 2.0 2.5, Turbo XT 2.5l etc.
I wanted to post some pictures of all of the different head gaskets, but the rules only allow for pictures after 15 posts. there are pictures on our website, I am not trying to solicit any one, I am only trying to post some info.
I thinks its a real positive that there has been a change made I truly don't understand why it took Subaru so long to make the change, We may try to put a set of these in one of our loaner cars with some modifications if time allows.