I will only need them on the intakes, and would like to keep the same retainers and locks. I am concerned about being on the edge or short on spring pressure. I am no cam expert, but this grind looks pretty stout. I am shooting for 300 to 335 on the seat, 800 to 825 at max lift. If the PAC 1247 springs will check at 310 at 2.050 and max coil bind is 1.130 or less, that is also a possibility, and would save some $$, I would only need eight springs.