Rear brake drum fit after turning down axle hub question

[Wade63]

Newbie question here so be gentle.
I'm planning a front disc brake conversion on my '63 C10 and will be going to 17 inch wheels. The center hub on the new wheels is too small for the rear axle hub so I was planning on having the axle hub turned down to fit the wheels. I've read of others on this site going this route. My dilemma is this--the rear drum center hole for the axle hub will then be larger than the hub and I assume this could be a fitment issue and allow water/dirt inside the drum. How are those of you who have gone this route dealing with fitment? Are there drums available with a smaller center hole that can be used? Can the "hub rings" be used to solve the problem?

I'm using 6 spoke Vision 141 Legend wheels with center bore of 87.10mm