Drawing changes

Some of my day consists of taking standard parts and making specials.

Typically this is just simple length changes per the customers requirements.

The question I have is with the way the drawing handles length changes.

If you have a partial view and the length is changed, why does the centerline and dimension not move with the end of the part relative to where they had been to the standard part?

The first drawings shows the part from the standard drawing.

The second drawings shows the part when, in this case, the part was made longer. The centerline of the notch of the tube is now where the end of the shorter, parent part would be given the new length of the part. Why does the centerline and therefore the dimension stay relative to this portion of the part that is in the view? This happens on several parts and several drawings when a part is either lengthened or shortened for a special.

If you had any suggestion how to keep the centerline relative to the portian of the view shown, I would appreciate it.

(FYI - in the second picture, you can see another centerline from a second view that has moved also, so it even happens multiple times in a drawing)

Thanks, Dale