Help on 360 build

Thanks rumble,
Here is my dilema.
I do not know what valve springs are in the head.Obviously they are set-up for the comp 268/454 cam,and they are new.

Would I be able to go to the Comp XE 268 or XE 274 without touching the springs?

I would think anything under 500 lift I would be ok,and both of them are.

I have heard good things about the XE 268 / XE 274.
Would these be a better choice?

Thanks