Wrong width drums will eventually cause a tapered condition.
[ame="http://www.sanjuan.edu/webpages/jasonkeith/files/Ch%2015%20Drum%20Brake%20Service%20TB.pdf"]http://www.sanjuan.edu/webpages/jasonkeith/files/Ch%2015%20Drum%20Brake%20Service%20TB.pdf[/ame]
View attachment Brake drum wide.JPG
See "I" below.
View attachment Brake drum wide2.jpg
I would think Bendix, Wagner as well as EIS are experts in this field.
I would guess they aren't talking about a drum that is any where near 3/4 of an inch too wide.