Don't think so on the stock tail blades. you will know when you hold the blade inbetween the tail blade grip. if there is side to side play then add one or two depending. But from what I can remember you don't need them. Remember with the N5 stock tail, Pay close attention to the size of the tail blades in regards to the size you can run in the event you decide to run aftermarket tails... I really recomend getting some carbon fiber tails, the heli will realy perform well... Good Luck,
BR,
Kevin