That's on their cams only, though. Or a cam with a similar profile.
Just to prevent any confusion.
Plus you need to factor in the mileage of your engine, and realize that valve springs won't stay in perfect form as the miles amount. It's a good idea to change them if you have somewhat higher miles on your car, regardless of what cams you are installing. I would say the exception being a very small cam that doesn't require revving over 6k.