422 dyno fail

You can buy a set of heads that are significantly better than what he has for $600-800??

No one likes it when I mention this, because it often goes against things they “know”........ but......
My friends Pontiac Stocker makes way way more power than this motor does(or at least what this dyno sheet says.....and is more than 500tq/450hp) with a 412” build that has heads that flow 220cfm, a cam that’s .420” lift at the valve, and the stock intake and carb.