IAG Performance IAG-ENG-1825 Stage 4 Tuff EJ25 Closed Deck Case w/Plugs, 14mm HSM. Fire-Lock, (No Bore/Hone)

IAG Stage 4 Tuff Closed Deck EJ25 converted case halves are the most cost-effective short block modification for high horsepower Subaru WRX and STIs. IAG machines the case halves assembled together in our Haas VF-4SS CNC mill 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 case halves are then CNC machined for our new Fire-Lock head gasket solution that is loosely derived from diesel technology where a counterbore step is machined around each cylinder bore allowing specially sized fire rings to drop into the machined area and head gasket bores. The Stage 4 Tuff case is then drilled and tapped to accept 14mm head studs that combined with the IAG Fire-Lock head gasket set greatly reduces head gasket failure during high cylinder pressure scenarios. 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.

This Part Fits:

Year	Make	Model	Submodel	Notes
2002	Subaru	Impreza	WRX
2003	Subaru	Impreza	WRX
2004	Subaru	Impreza	WRX
2005	Subaru	Impreza	WRX
2006	Subaru	Impreza	WRX
2007	Subaru	Impreza	WRX
2008	Subaru	Impreza	WRX
2009	Subaru	Impreza	WRX
2010	Subaru	Impreza	WRX
2011	Subaru	Impreza	WRX
2012	Subaru	Impreza	WRX
2013	Subaru	Impreza	WRX
2014	Subaru	Impreza	WRX
2004	Subaru	Impreza	WRX STI
2005	Subaru	Impreza	WRX STI
2006	Subaru	Impreza	WRX STI
2007	Subaru	Impreza	WRX STI
2008	Subaru	Impreza	WRX STI
2009	Subaru	Impreza	WRX STI
2010	Subaru	Impreza	WRX STI
2011	Subaru	Impreza	WRX STI
2012	Subaru	Impreza	WRX STI
2013	Subaru	Impreza	WRX STI
2014	Subaru	Impreza	WRX STI
2005	Subaru	Legacy	GT
2006	Subaru	Legacy	GT
2007	Subaru	Legacy	GT
2008	Subaru	Legacy	GT
2015	Subaru	WRX STI
2016	Subaru	WRX STI
2017	Subaru	WRX STI
2018	Subaru	WRX STI
2019	Subaru	WRX STI
2020	Subaru	WRX STI
2021	Subaru	WRX STI