Fueling & Injection - Is fuel pump and injectors needed after cam and head swap?

Do most of you guys upgrade your fuel system after heads and cam? Whats the limit on a stock fuel system on an ls1?

I don't think it is something you would say is "mandatory" after doing a H/C swap.. The stock injectors probably are being pushed when it comes to duty cycle though. I'm on stock system right now. Right around 500bhp.