Hi Tony --
I've helped both sellers and buyers in East Austin regarding properties with foundation issues. There is always an extensive list of potential repairs that could be needed after leveling. Besides plumbing, windows, flooring, and walls could crack, doors/window become inoperable, etc. The severity of the foundation deviation and age/material of the plumbing may give you some insight. Ask your foundation company for their statistics or have a plumber give you their assessment before you begin work. I think their expertise would be beneficial to you. Also, the foundation companies my clients have worked with offer a plumbing check after the level to check as for leaks/damage as part of service. I wish you all the best!
"The First Lady of Austin Real Estate"