The root stock should grow as it was destined to on genetics. They can become just as large.
This is the negative to purchasing grafted trees without being able to chose what root stock that they have been grafted onto.
Rick
"Many times a day I realize how much my own outer and inner life is built upon the labors of my fellow men, both living and dead, and how earnestly I must exert myself in order to give in return as much as I received"
