As stated before the 3/4 cam was the flat head era not a 3/4 mile track pretty sure junkie knows that
Headers are a 1/10 to 3/10s all else being equal on the tune with or with out on a 340 1/10 for the pinch on the drivers side
Why did my stock 60 gts 340 727 3.23s 80k miles beat the 70 duster...