You can also measure the distance using DesignLogic, use the small arrow on the right of the input field.
You can set motion to "point tot point".
You can use the Replace Face command.
You can delete the face.
Use your imagination! There are so many ways to do this.
I agree with both previous suggestions. The simplest is Replace Face. It is a geometric definition rather than finding just the right value.
Do note though that snap to object is not associtive. Replace Face or Make Coplanar are associative and have the benefit of a geometric definition rather than a value.