My slant 6 has dual exhaust. The headers are 6 into 2. The pipe from the collector for the front 3 cylinders runs down the drivers side and the pipe for the collector for the back 3 cyclnders crosses under the tranny and runs down the passenger side. I also have an H-pipe right at the end of the tranny. FRom the H-pipe back everything is routed just like a v8 dual system.