67 Dart GT w/ 340 - what headers?

Go with Dougs.

1... They don't loop under the steering linkage, so you won't be replacing them every 2 or 3 years because they get road rash.
2... Ceramic coating looks way better.
3... Autozone has a 20% off sale every couple months, that'll get you down to about $500.
4... No issues with shifter linkage.