I say if at all possible use pro-x or oem pistons. If your running big ponies, nitrous etc, then use wiseco's. They are both excellent pistons but I would never run forged unless the motor absolutely required it. Same thing car manufacturer's do also. Dodge switched to cast pistons in their viper a few years back and I believe gained horspower, the new corvette C6 uses cast pistons, Porche uses cast pistons. Why? If the engine can run a cast piston it will run more efficiently, run quieter and be more reliable.