Ok, the only thing my brain just keeps going to is BIGGER IS BETTER. I want it to flow as best as it can, even though my setup isnt crazy. Did they use headers on the race hipo/d-dart 273's???
Bigger is not always better , put 2" or 2 1/2" headers on your stockish dart and it will be a dawg , you might get 8 0r 10 hp more with headers on the 273 , that's might , most of the driving range revs you'll gain nothing .