/6 single or dual exhaust?

This is a late message, but I finally got my son's Dart up and running. I took you advise and went with the thrush and Clifford headers......WOW!!!! It sounds like a small V8.. Most people think it is a 318.. I opened the valves, upped the compression, and made a 2bbl set up. He is terrorizing the subdivision doing laps...His smile says it all!!!!!!! Thank You, Thank You, Thank You..I am officially the best Dad in the world. We went with citron-yells go-wing, slit scoops, and chromed rallies. He got creative with the interior and we used seat covers that are black and yellow, Also dyed the door panels yellow, and everything else black. It looks like a Dick Tracy mobile, only my son has no idea who Dick Tracey is. I'll get some pictures up on my build. Everyone was such a great help.