i pulled out an old september 1970 popular hot rodding mag where they did a chassis dyno/drag strip test on a '70 4spd 6pak dodge. car made 244hp@4250rpm at the tires stock. car ran 13.95@100.78 with 4.10 gears. they dyno tuned the car and got 272hp@4250rpm and ran 13.74@105.63mph. then they took the car to a header shop and put on some 2 inchers. car made 318hp@4750rpm an ran 12.92@108.42mph. 74hp gain in total; pretty cute. i think the car could've 110+ if it hadn't been over geared.

i really don't have much of a dog in the manifold/header fight; i use both. but, this has been going on for decades. i remember hanging out at the chassis dyno shop in '68 and '69 and it was the same argument. seems like nothing is solved but if your a manifold lover then power isn't as straight forward as the common culture dictates. otherwise, you'll have to use your head rather than your gonads. this is also got me thinking back to the late '90's and chassis dynoing my r/t. it made 325hp between 3900rpm and 4300rpm and then fell off a cliff. what would a few hundred more usable rpm (like the '70 dodge) have netted me with a better exhaust? or, would the automatic transmission ate up all the gain?