I am pretty sure there is a formula where you can calculate your horsepower by how fast you accelerate from the 1/8 mile to the 1/4 mile.

Let's call that the "back half".

If your car ran 4.05 seconds on the back half and weighs about 3700 pounds,how much approximate horsepower would you have to do that?

I've never heard about using that number, but I just used the Wallace HP calculators using 1/8 and 1/4 ET. Those came up with 673 and 668 HP, respectively using ET. Dyno sheet on my wall here says 662. Not bad!

The calculations based on MPH were lower and not as close. I'm sure a Stocker like yours would not look as good based on MPH either.

http://www.wallaceracing.com/hpcalculatoreigth.php

http://www.wallaceracing.com/hpcalculatorquarter.php

For 4.70 cars we used 1/8 x1.575.as et goes down that number doesn't work.i think you could just ratio i