| Subaru EJ257 2.5L DOHC (Stock bore) |
WRX STI 2004 and up | |||||
| Stock Bore: 3.917, 99.5mm Stroke: 3.110 Rod: 5.137 Head cc: 51.0 Gasket: .050 Deck: ~.012 | ||||||
| Bore | Comp. | Dome | Compression RatioComp. | Gram | Part | Required |
| in/mm | Height | CC | w/ Stock Head | Wt. | Number | Ring Set |
| Dish top | Turbo/Nitrous | |||||
| 3.9175 / 99.50 | 1.208 | -16 | 8.6 | 406 | 3620301+ | 1215283917 |
Offset pin hole.