i was wondering what the 5.3 stock internal are, cast? hyper? how much boost can they handle and how much power?

 

i think they are forged.....someone else with a lil more knowledge should chime in....

 

Not forged. Here's what 9psi does to them if you run a little lean.

 

so does anyone know if they are Hypereutectic or if their just cast? and anyone know about how much power they can handle without putting different pistons in?

 

A lot of people are hitting well into the 500rwhp range and not having issues as well as a few over 600rwhp. Tuning become critical at the point, as well as basic understanding of how your motor is working and when you shouldnt be hard on it.