I'll bet they weren't running 30psi on a cast piston in a combustion chamber designed in the 50's though. And I'll also bet they were stretching the truth a bit on the amount of boost they can handle. It's the internet. If for no other reason, forged pistons give you some engineering margin if your tune isn't perfect out of the box or if something goes awry. Multiple people have recommended forged pistons if you want to do it right, once. Take it from me, I've cut every corner known to man and paid for it each and every time. Wait a little while and do it right. For every 25# of boost on cast piston story, there are 19 you don't see about melted pistons the first time they hit the boost without the right tune, right ignition system, or inadequate fuel delivery.
