This page may help you.
So one way that would work is equip the Power Anklet item onto the female vulpix who has 31 speed. Breed that with a male or a ditto and produce a male vulpix with 31 speed. Give the male a power anklet and the female either a Power Lens or a Power Band. The child will have 31 speed, and either 31 SpA or SpD,
guranteed. Then its just a matter of also getting the other one (SpA or SpD), but that chance will be high due to one parent already having it just not
guaranteed like the others.
So the thing is its impossible to guarantee 3 IV's being passed but 2 are guaranteed with the other one happening soon enough (shouldn't take too many eggs)
Sorry if this is a bit confusing, PM if you need more help!