i can lead you to believe that everything is all roses and butterflies in this situation. but about 95% of the time the answer in No. if your into a girl, she has become comfortable with the friendship you have and she wouldn't want to risk that.
the better question is can close friends who became lovers and have now split up still remain friends. You need to think about the aftermath before you decide to go forward especially if this friend is very important to you. A break up can make things awkward even if you think there is no way you two could ever stop being friends...it can happen.