Denny,
In all the years I did drum brakes I can't say I ever worried about arcing the shoes, they just wore in. I'm not saying it's a worthless idea,just that in all the years I twisted wrenches I never ran into the need for it.
It's too bad you can't find a shop that will turn off just a little of those drums cause that's what I'd want to do.
See Burger King, they'll do it your way !
Other than that I can only think of shoe material and that thought came to mind because of disc brake pad squeal,especially on Corvettes that was sometimes only cured by changing the pads to a different manufacture, which I spose changed the pad material composition.
Dan
