Hell yes headers will always be better. I went from stock manifold then a stock manifold ported it out to 2.25 felt a little bump. Then custom duals made from the stock manifold made bigger difference over the stock manifolds i would say 10 H.P then i went straight headers and god damn pulling in the 3500-5500 range was way better. But i would say there is the cons of headers leaks of course but i use remflex gaskets havent had any problems. My Dart is a daily driver so i added water cooled plate under the intake. With the duals i had more room in the engine bay to adjust my gear box and clutch rod, headers made it more of a ***** cause of the smaller engine bay in the early abodies. Check on ebay i seen some slant six headers selling for 250.00-300.00 range.
