IAG Stage 4 EXTREME 2.5L Subaru Closed Deck Short Block

The IAG Stage 4 EXTREME 2.5L Subaru Closed Deck Short Block is a professionally built and assembled engine block designed to handle increased power and torque. It features brand new Subaru OEM case halves converted to a closed deck design, IAG Fire-Lock receiver groove machining, and is bored and honed to 99.75mm.

Key components include IAG-Spec JE FSR forged pistons, H13 performance wrist pins, IAG Spec Tri-Beam connecting rods with ARP625+ bolts, ACL rod and main bearings, and a Manley Billet Turbo Tuff Crankshaft. This short block is machined to accept 14mm head studs and requires IAG Fire-Lock Head Gaskets. The compression ratio varies depending on cylinder head selection: 8.2:1 with B, V, and W cylinder heads (EJ257) or 8.5:1 with D cylinder heads (EJ255).