How easy to get 500 horsepower w/ stock stroke 440?

I'm building a stroker. got down to shipping address and Hughes engine said, oh wait ! you live in washington ? I have an AZ. cell phone number. he said that the crap pump gas up here will cause detonation OVER 10.0 to 1. so we changed the build from 10.5 to 9.98. still plenty over 600hp. and that's with Edlbrock RPM heads. like said before, iron heads and even lower CR. One of my build criteria was to run on pump gas. Not sure why gas mileage was mentioned in the same thread as 500+ HP, but can always get a Gear Vendors Over Drive..