Headers! 1969 Barracuda Notchback.
About 1980, I took the beat up headers off my first 73 Dart 340 Sport with manual 3 speed, replaced them with new Hooker Competition Plus and they rattled against the frame and probably other stuff. Took them off and replaced them with stock manifolds. Stockish low compression 340 seemed to run better than ever. Dropped the ride height a little. No problems and I liked the looks better. No regrets.