You're arguing with the wrong guy haha, I'll still be running the Kakimoto exhaust anytime over some brand I've never heard about, you just listing me a bunch of spec's that have nothing to do with the topic at hand, when I referred to sheet metal, I meant the shape, the actual stamped parts, they are the same, and yet you argue about engine specs? You're funny guy Mr "Impul" LOL maybe I should change my name to Autech. You seem to enjoy flexing your brain knowledge about the K13 very good, here's me who comes along and knows just as much if not more. Nuff said