The Stage 4 Extreme is IAG’s strongest and most prepared EJ25 Closed Deck offering. The case halves are split and the main webs are CNC machined in our Haas VF-4SS CNC mill for 9.5mm pins to reduce distortion and movement of the case in extreme conditions. The case halves are then reassembled and IAG machines the case to accept the IAG CLOSED Deck Inserts that transform the block into a solid deck. The unique inserts feature small passages that allow needed coolant flow to the deck surface. The short block is then Deck Plate bored and honed to 99.75mm in our in-house Sunnen SV-30 the most advanced automotive cylinder hone available. IAG’s in-house honing process is able to set custom piston to wall clearances to best fit your needs. IAG’s Closed Deck is suitable for street or race use and has been tested in vehicles producing 1000+ horsepower and over 55psi of boost.

What’s Included

• (x1) IAG Stage 4 Extreme Closed Deck converted EJ25 Case
• (x8) Threaded case bolt plugs
• (x1) Bored & Honed to 99.75mm
• (x4) JE pistons (99.75mm)
• (x4) Manley Tri-Beam rods
• (x1) Machined for 9.5mm pinned mains
• (x1) ARP Case Bolt Set
• (x1) Line Honed Mains
• (x1) Machined for 14mm Head Studs (14mm Head Studs sold separately)