S cam rollers

The rollers are 32 mm fitted new by me when I did the drums and shoes they’ve done 100,000ks on the drive axle ,as above 10mm left on shoe centres perhaps 15 mm when new ,drum Hardley worn ,but the rollers are very high on the cam ,all seems a bit odd ,there’s only one drum listed for this axle .shoes are 8 inch quick fits .