The last 4 EVs should go into Defense as it gives you an Odd HP Number, which makes you come in on Stealth Rock for one extra turn. Putting those EVs in HP would limit your switch ins to 4 instead of 5. If this is for LV 50 variants, if your current HP is at an odd number, keep it that way, otherwise, add the last 4 EVs in HP to see if the number changes