Another important thing is that standard shoes OD may not be big enough to suit drums that have been machined a few times. I have a couple of bikes that have had so much machined from the drum surface that by the time I have reshaped standard shoes to that diameter, the cam moves too far around to work well. On these bikes I have had extra thick (6mm) linings fitted to the shoes and then machined the linings back to suit the diameter for the drum, so am getting 100% contact area. Lots of trouble despoking and respoking to machine the drum and sending the shoes away for relining, but the results are amazing.
The relining was done by some place in Brisbane. I arranged it through a local (Gladstone) car brake/clutch repair workshop.