Different dynos, and different operators, on different days. It's easy to fudge dyno figures. Flow bench too. That's why the real deals are the track results. Because it will always take "x" horsepower to accelerate a given weight to a MPH figure over a given distance. No way to fudge it. Reality sucks when the engine with 330cfm RPMs on a dyno'd 600hp 408 in a 3300lbs car runs mid 11s.
