And here's a great example of moving from -1 to -13's. Greg's combo is on limited passes and it's making great power too. Any time you want to slow down and swap on my -1 heads just let me know! lol No doubt it'd benefit from some Ti valves but, this isn't the first of it's kind to run SS. Most people will reference a cars performance to how much power the motor makes but, it's more a matter of WHAT ARE THEY USING OF WHAT'S AVAILABLE. I find there's a bunch of power available in the rest of the car. What was the original post again, lol? Thanks again Demon for sharing the details of your build.