If I had to stoop to the level of others here and do this manually I would use a piloted counterbore tool similar to the attached picture.
McMaster-Carr offers these tools in an interchangeable pilot style including 11/32"

Cutters:

https://www.mcmaster.com/counterbores/high-speed-steel-changeable-pilot-counterbores

Pilots:

https://www.mcmaster.com/counterbores/steel-pilots-for-changeable-pilot-counterbores

If one has a lathe handy an old valve stem could be easily made into an extended length pilot.
Attachments
IMG-2045.jpg (110.12 KB, 94 downloads)


1952 1300 Canadian 1/2 ton restomod
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