Subaru STI EJ257 Pistons & Rods Kit - Manley Platinum Series Pistons & Turbo Tuff I-Beam Rods Complete with Manley Performance Platinum Series Pistons and Turbo Tuff I-Beam Connecting Rods, this kit is made to take the EJ257 engine in your STI to the next level. Manley pistons are machined of high strength 2618 material. Each design is lightweight yet robust enough to deliver long service life. Offset wrist pin design is utilized for quiet start-ups. Perfect ring groove to skirt squareness is achieved through our unique "one fixturing" manufacturing method that assures maximum horsepower. All pistons come with moly coated skirts. Round wire locks, premium chrome moly wrist pins, and premium steel top ring sets from Total Seal are included with every kit at no additional charge. Manley Pro Series connecting rods are forged from aircraft quality 4340 vacuum degassed material. Each rod is fully machined in the Manley Lakewood, NJ factory to the highest standards. Our signature "Turbo Tuff" design combines the appropriate weight and rugged strength for ultimate horsepower applications. Each rod is shot peened after machining and magnafluxed. Bores are round and without taper. Bend and twist is tightly controlled. Cap fasteners are 3/8" APR 2000 cap screws. Features Pistons: 2618 high strength material; Lightweight design with offset wrist pin for quiet start-ups Pistons: 2.500” x .180” wall Premium Chrome Moly pin (Standard Series) included P/N 42346 Pistons: Pressure balance groove Pistons: Will accommodate +1mm valve sizes Pistons: Premium Steel top rings with Napier seconds and round wire locks included Connecting Rods: Forged from 4340 aircraft quality vacuum degassed material Connecting Rods: Shot peened after machining to MIL spec and 100% individually magnafluxed Connecting Rods: Specifically designed to handle high horsepower applications when using turbos and/or nitrous Connecting Rods: Fasteners are 3/8” Connecting Rods: Flywheel horsepower range for these rods in a 4 cylinder application is 1,000+ Benefits Optimizes engine performance Rugged strength and durability Designed to handle high horsepower Applications 2004 - 2021 Subaru STI What's In The Box? 4 - Pistons & Rings 4 - Connecting Rods & Fasteners Warranty Manufacturer Standard Warranty