I finally pulled the short block (SOA478H600R1) that I purchased a couple months ago out of the box and put onto a stand. Changed out the 7mm oil pump for a 9mm that I had (I don't think I'll need a 10mm as I'm a conservative driver, and this is just for a DD project). Looking at the pistons, they're labeled as 255 SH. Is this going to be a problem mounting with DOHC heads? When I was talking with a subaru parts tech over the phone I had specified that I wanted an EJ251 or EJ253 short block for '03-'05, and they had given me the part number. I had then talked with a different Parts Tech, and they confirmed that that part number was for what I had specified. Are the pistons the same? I thought the 255s were used with the AVL systems, and can't work with pre-AVLS. . Should I be looking for new pistons now? 

The current motor in my car is an EJ from a 2001 Impreza, with DOHC heads. I wanted to recreate the build as it is generally a nice and powerful (enough) motor. 

Also, I bought a brand new subaru water pump because I thought the stock one that came on the block was supposed to be forward facing.... What showed up is identical to the spare I bought. They are identical, right? 

 

Thanks all,

 

Greg

 

Edited July 19, 20214 yr by suprunner

Negative. Those are not 255 pistons. 

GD

Thank you! I'll start assembly then.