Let me just say that Skunk2 has the WORST customer service and the employees that work there know nothing about the products they sell. Their literature is incorrect regarding cam timing and their cam gears have sloppier keyways (allowing more than 2 degrees movement) than OEM or Crower. Their titanium retainers weigh much more than Crowers or Manleys but their valves actually look pretty decent. All I can say is beware if you buy their stage 2 cams and follow their instructions....