magnum camshaft and spring lift

Springs and valves are only part of the equation. The reason for the lift limit is generally spring retainer to valve guide interference


Yes, you have to have your "head guy" make sure that there is enough lift in the heads. He should check how much room is between the valve guide/seal and the spring retainer, so they don't bottom out at max lift. In addition to making sure that your springs can handle it without getting into coil bind.