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 fresh 340 intake carb headers 3.55s bigger tires then me at the drag strip tune and driver.
340s dont pick up 5/10s from headers maybe a stock big block gets 35 hp if the manifolds or the exhaust is 1 7/8 and suck
5/10s across the board total bs