Calling all 60-2 Valiant and Lancer owners, info needed

For exhaust I am using P/N 3614368 (left) and 2863549 (right) manifolds off a '69-'70 Dart with a 340 because I think they are the only manifolds that will fit, and it was easier and cheaper than trying to use headers. I don't think they flow very well, but I'm not sure. What say you about these manifolds, Mopar guys?