Item master & Branch plant

Hi,

I have a query on Item master and Branch plant.

We set up an Item with the GL class code as 'ASP' and also to B/P's.

Later we realized that GL class which we set up was wrong. So we changed the GL class code.

Now we can see for the few B/P's new GL class code has been updated but most of the B/P's has an old GL class code.

Upon changing the GL class in the Item master, Will the changes reflect in Branch plant as well? Or

Do we have any standard report to change?