The XE268 (the one I'm looking at) has a Basic Operating RPM Range: 1,600-5,800 RPM. So that is close to 6000 but I'm still concerned about the starting RPM range which is 1,600. I've looked at other cams that start at Idle or 600 RPM and they seem to be like RV or Tow cams. So I think that I am on the right track far as a good performance cam. I still have to learn more about cams before I purchase. So I still have plenty of time and will learn somethings along the way. Lunati has a cam that has 268 duration on the intake and 494 lift on the intake with a staring RPM of 1,800. The Comp cam has 268 duration on the intake and 477 lift on the intake and a starting RPM of 1,600. So I'm like would 200 RPM make a difference and also why is the duration the same but the lift is more on the Lunati? Will the Lunati cam make more horses? Questions, questions??