Revolver Exhaust Manifold Header FOR 91-99 Jeep Wrangler 4.0LDescription: Non deforming manifold outlet seal Self aligning exhaust seal will never compress or blow out Bolts easily to stock exhaust "Revolver" Collector Design with extended center tube is designed to pull the exhaust pulses from the engine for crisp throttle response on the draw Manifold tubes fully welded Each tube is welded to the flange twice, inside and out Super duty manifold flanges 1 2" thick flanges never warp or crack Computer