The width of the interior plate of the 40-049 replacement lockset is 7/8", note that the exterior plate is the same width. Take a look at the following picture that shows the interior plate with the width dimension.

alternate view of 40-049
The width of the interior plate of the 40-049 replacement lockset is 7/8", note that the exterior plate is the same width. Take a look at the following picture that shows the interior plate with the width dimension.