LOL. My small block Duster goes 940's@138 mph (2860 pounds) and I don't think I even have 670 horsepower. But then again all I care about is the ET slip. Maybe after this Winters upgrade I might be there.
Just to show how skewed the calculators can be I plugged your specs into the Wallace Calculator. Speed and weight got you 579 hp. ET and weight got you 680 hp. Now if the calculator were a accurate measure, both HP numbers should be close to the same. The same engine on 2 different dyno's net different results.
