I am running the zo6 springs now. Someone told me if i change out the gt2-3 cam I have know to this cam I will need to change my springs again to 918s what you guys think
Comp Cams XTREME RPM HIGH LIFT XR275HR - 222/224 - .566/.568 w 1.7 rocker - 112 LSA

 

The gt2-3 lift is .571/.578, which is more than your new cam, so I don't see why...

EDIT: This assumes you are running the yellow springs and not the blue ones. But since I'm pretty sure the blue springs will not work with the gt2-3 this must be the case.

 

I believe that the Comp cam has a faster ramp rate and that's why they recommend the 918's which have more seat pressure than the LS6/Z06 springs. Lift isn't the only thing to consider when chosing valve springs, you also have to factor in how agressive the cam lobe is.