It took a min, to figure out. The hedders came with the engine, then its blued stainless tube two pcs of stirene rod heated over a soldering iron and bent to 90deg sized and glued together to form the S. Then the long tube. I make some from the head out to but they take a long time. you can make a couple of bends in a rod but not to close together because the heat effects your first bend, that is when things need to be cut and pieced back together with the next bend. This set was one bend and add the collector.