Upgrades to my stock 273 67 Dart GT
i used a summit own brand header back dual exhaust kit on my 68 valiant. it included mufflers and came all the way out the back. it has slip fit joints and comes with clamps so nothing more to buy. the tail pipes need to be cut to length/preference under the bumper and in my case the middle pipes also needed shortening but that's just because valiant's are shorter wheelbase so won't apply to you. all in all a good kit that was easy to fit at home.
neil.