The hot rod cams that we installed state that they are NSR (no springs required) cams. I'm sure if we would upgrade the valve spring, seats and retainers we will pick up noticeable horse power in the higher RPM rage. As for your Appalachian to best reach the goals that you have for your car. I would like to sit down with you and pick a cam out together. We would pick cams that best fit your needs. Either custom grind cams or pick one of the many cams that comp cams offers for your application.