The consumption manifold is one piece, the spark plugs are just one phase colder when compared to other STIs. The exhaust is different with the USDM WRX down to the headers. There's no immobilizer for these versions. The EJ20G and EJ20K are two decades old at enough time of producing, https://ej20stiengineforsale62581.blogsumer.com/28833586/how-much-you-need-to-expect-you-ll-pay-for-a-good-ej20-sti-motor-for-sale