Brian,
that is what I am trying to find out. This is a known exchange for the 1/2 Ton but I don't know if the 1 Ton's backing plates can be interchanged from 53 to 51. My concern is that I will get it on the road someday, and as soon as 1 front drum gets scored or whatever, I will have to park it. With the 53, the drums are available new.