Bradford Pears do not live very long.
http://www.dirtdoctor.com/view_question.php?id=1154 Note that the western type is best. We have one in our yard that my husband and his brother took the lower branches off years ago. They didn't know any better. They cut them close to the trunk, but the holes that resulted are not real noticeable due to the nature of the bark. Currently, the lowest branches are about 7 feet from the ground. It's about 35 + feet tall.
I regret that I have nothing more to add. I am not familiar with such a thing. You might give the Dallas Arboretum a call.