The IAG 1000 FA20 DIT Subaru Closed Deck Short Block is built for enthusiasts who want big power without sacrificing reliability. Designed to support up to 1000 BHP, this combination delivers the strength needed for serious boost while maintaining the durability required for real street use. Inside, you’ll find IAG-Spec H-Beam forged connecting rods paired with IAG-Spec JE pistons featuring an electroless nickel-plated coating and H13 tool steel wrist pins. The case is precision-machined to accept our proven Fire-Lock head gasket system and 14mm head studs (sold separately). Each IAG 1000 short block is hand-assembled using ACL or King rod and main bearings for consistent, reliable performance, whether you're street driving, drag racing, or out on the track. The IAG 1000 FA20F Subaru Closed Deck Short Block features our proprietary “Fire-Lock” Head Gasket System. This system has been proven in our record-setting race cars to be the strongest Subaru head gasket system ever produced. To achieve these results, our engineers separated combustion sealing from the oil and coolant sealing functions of a traditional head gasket. Each cylinder is precision-machined with a counterbore step at the top to accept the Fire-Lock ring that mechanically locks into place and creates an extremely secure combustion seal. The independent gasket bodies handle sealing the oil and coolant passages, keeping fluids out of the combustion chamber where they don’t belong. The entire assembly is secured using 14mm head studs for maximum clamping force (Fire-Lock Gaskets and 14mm Head Studs sold separately).

1000 FA20 DIT Subaru Closed Deck Short Block Includes: Case Halves - Converted to Closed Deck from brand new OEM Subaru case halves, bored and honed to 86.25mm., Fire-Lock - IAG Fire-Lock receiver groove machining, the latest solution to prevent head gasket failure on high horsepower and high boost Subaru's - Requires IAG Fire-Lock Head Gaskets that are sold separately Part# IAG-ENG-1755, Head Studs - Machined for 14mm Head Studs - Requires 14mm Head Studs that are sold separately Part# IAG-ENG-1711, Pistons - IAG-Spec JE FSR 86.25 2618 Forged Pistons, Electroless Nickel Plated Tops & Ring area, Ring Set, .250" H13 tool steel wrist pins, Clips, (Perfect Skirt Coating and Offset Wrist Pins)., Connecting Rods - IAG-Spec H-Beam Connecting Rods with ARP 625+ rod bolts., Rod / Main Bearings - ACL or King Race Bearings, Crank - Subaru FHI FA20 Crankshaft, Case / Main Bolts - Standard FHI Subaru case bolt.