How much machining and polishing work goes into a stage II LS6 head. What I'm trying to ask is how hard it would be to machine by oneself. My dad owns and runs a machine shop with many CNC machines. He said it wouldn't be hard to do. What exactly would need to be done. Does anybody have stock numbers, and after numbers of the intake and exhaust ports? What else would need to be opened up besides the i/e ports? If I did a h/c I would be looking for 450+ rwhp with a G5x3 cam or something similar, any input?