Hello PMvalente,
The pieces you are refering to are pieces to alter the roll center of the car.
The higher numbers make the roll center of the car higher. The roll center is the point in space where your car rolls around in turns.
Sorry for the not so complete explanation but if you do a google on "roll center" you will find more then enough info. For the remainder I would suggest you try it yourself to see what it does for you. I'm going to try it as one of the next steps to get to know the car better.
Ciao,
Spiller