I am putting two air bags in my rear suspension. I bought them from a board member a while back and i have no instructions. I did a search and know that the nipple for the air line goes down but they also have two plastic round spacers . I need to know if i need to use this plastic spacers and where do they go? i assume the spacers go where the nipple on the bag is but i am not sure..thanks for any help.............................Bob