APDTY 12637060 Exhaust Manifold Cast Iron Assembly Fits V6 4.2L Engine On 2008-2009 Chevy Trailblazer GMC Envoy Isuzu Ascender Saab 9-7x (Replaces 12637060, 12587310, 8-12587-310-0, 8125873100) Heavy Duty Cast Iron Design Last a Lifetime Exact OE Fit Form & Function