nice I asked brad about the fixed cam gears his response was "Vernier adjustable sprockets #306560 are not a necessity with Stage 4+ cams, but as they are way more accurate than the constantly advancing and retarding factory sprockets you get a better tune and better results out of your camshafts." so I went with the vernier gears also my tuner basically said the same thing and gave me examples of people running the vct still with stage 4 plus cams but both were auto's