The old shoes of course had full contact. I don't have a measurement for the drums after turning. The shop that did it has always my shoes or rotors that would be out-of-spec after turning. I'm sure there is only limited contact with the new shoes. I will carefully drive it for a month to see whether the stoppin power increases. In the "old days" you could get your new shoes machined to fit the old drums. I don't know whether there is now a business that can do that.
