Anyone else use 2 gaskets for joining up pipe to headers.?? Ive fitted just one and it leaks then I noticed this on their website, I've copied this from their website...... GTSPEC Gen II exhaust manifold gasket set. Set includes 1 x uppipe to turbo gasket, 1 x downpipe to turbo gasket, 2 x block to manifold gaskets, and 2 x manifold to uppipe 3 bolt gasket. This set is part of GTS-PER-1016 (Gen II manifold for EJ207/EJ257 Subaru Engine). We suggest to use two 3 bolt gaskets on our header system for the best seal.