The SP-534s are officially discontinued, and the SP-580s are their replacement. The two are fairly similar, with the only major difference being that the SP-580s have a tighter gap. The SP-580s can still be used in the 5.0L F150s. You will need to regap on naturally-aspirated F150s, since they need a wider gap. For supercharged F150s, you'd probably only need to verify their gap.