EJ257 Short Block Engine Assembly

The Subaru EJ257 short block is a brand-new, genuine OEM fully assembled short block, specifically engineered by Subaru for the WRX STI. Part number 10103AC870 represents a direct-fit OEM assembly for various Subaru models including the WRX STI (2004–2021), WRX STI Hatchback (2008–2014), Forester XT (2004–2013), Legacy GT (2005–2012), and Outback XT (2005–2009). Crawford Performance states that the OEM EJ257 short block is a robust foundation and not the weak link in Subaru engines; issues often stem from improper tuning, neglected maintenance, or mismatched supporting modifications. They suggest that with proper maintenance and a solid tune, it can safely handle up to 400whp/480bhp. For those looking to build a higher-horsepower engine, this OEM block can be combined with CrawfordSPEC pistons or a piston/long rod combo to assemble a short block capable of handling up to 600whp. Engine Gasket & Seal Kits are sold separately for this short block assembly.