Another point,,, just because a spring is listed with the right seat and open pressure doesn't mean it is a good spring. Material and spring frequency are very important.
Go with a very well known brand, make sure they match your rpm and cam needs, and find out if there is a beehive type that will fit your application as well. The Beehive springs have proven themselves to be superior in most applications, and I would think this is one of them. I am not saying they will make more power, but if there is any trouble with the springs in use at all, they can bring back any lost power. Also they are known to allow more revs with the same seat and open pressures. As I understand it, a beehive spring has no frequency issues like a straight spring, because the frequency is always changing due to the taper. A poor straight spring with the wrong frequency can raise havoc at those rpms. For instance, I run a spring with a frequency that shows up at 2,000 rpm, (no problem), 4,000 rpm, no problem here since I launch at 5,000 and trap at 7500, and the next frequency cycle is 8,000 rpm. So My valvetrain is happy. In the past I have bought cheap springs that didn't last three weekends, on a motor that never saw more than 6300 rpm!