closed chamber 714 casting 318 heads

Holy crap, 58? I might be in trouble lol. I was hoping to be at just 8.5 CR I guess we will see. Gas is getting more expensive so I want to run the cheap stuff. I've read good builds that make good power on 87 octane. I suppose if it pings on 87 I'll.go up to 89. Hopefully no more haha. I was hoping that the swirl design would atomizer the fuel better for mileage. I'm hoping to break into the low 20 range. In the future I might bump the compression up and run E85.