Grimmspeed Exhaust Manifold to Up Pipe Gasket 2X ThickGrimmSpeed OEM Style Gasket, OEM quality without the high OEM price. FINALLY you have an option for an extra thick Exhaust Manifold to Up Pipe Gasket. The most troublesome mating joint in the Subaru exhaust track is the manifold to up pipe connection. So what did we do? Well lets just say we made a gasket that is as thick as Sarah Palin's accent. More than 2x thicker than the OEM. In all, it is 2. 5mm thick.. a monster compared to the 1. 2mm thick