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2010 XT Auto
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118 Posts
Discussion Starter · #1 ·
part # 10103AD020

Can I use this short block with my 2010?

I am getting confused on which short blocks I can use? It looks like there are very subtle differences on some.

thanks
 

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2001 Forester S, 4EAT
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2,923 Posts
If you look here: Subaru EJ engine - Wikipedia it will show that it was used in the older Forester XT models, MY 04-05. If you plan on using it, you'll need to hack your ECU, etc.....IMHO, I would not use the EJ257 engine in your MY 10. You should be looking for the EJ255 short block.
 

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2010 XT Auto
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118 Posts
Discussion Starter · #4 ·
I read all those links but didn't see Type RA discussed.
Why wouldn't you use it? Why only 255. I know compression a little different and I would get a tune
Thanks for replying
 

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2004 Forester XT Auto
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345 Posts
If you look here: Subaru EJ engine - Wikipedia it will show that it was used in the older Forester XT models, MY 04-05. If you plan on using it, you'll need to hack your ECU, etc.....IMHO, I would not use the EJ257 engine in your MY 10. You should be looking for the EJ255 short block.
"Hack your ECU"? It's just a simple tune at most...and regardless, the 255 and 257 SB's are functionally identical with small piston differences, in fact IIRC the 257 has a lower compression ratio to handle the higher boost of the STI. I don't know of any reason you couldn't run a stock tune with a 257 SB in place of a 255 SB, all else being equal.
 

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2005 SFXT
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9 Posts
@Galaxywide

Just turned a little over 2,000 mi on the 2018-19 RA SB that replaced the 255 in my 05 XT. No tune yet. I will get it tuned as soon as I change out the up pipe to the catless. Otherwise all stock.

Was told that tune wasn't needed yet as the CR difference is negligible
 

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2010 XT Auto
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118 Posts
Discussion Starter · #7 ·
@Galaxywide

Just turned a little over 2,000 mi on the 2018-19 RA SB that replaced the 255 in my 05 XT. No tune yet. I will get it tuned as soon as I change out the up pipe to the catless. Otherwise all stock.

Was told that tune wasn't needed yet as the CR difference is negligible
thanks for verifying. I am picking my block up this week
 
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