Mill to 1" bars

[midnightcafe]

Sounds fine, as long as you don't find yourself on Laguna Seca or Monster Jam... cut up an aluminum can as a shim to fill the gaps, I doubt you'll get perfect contact using a drill

[Zook]

There may be an adaptor available or you could make one from aluminum.
Just bolt onto the top tree and then install your choice of bars. Serves as bar risers, also.

Much safer than having just 1/16" of material.

[SqDancerLynn1]

I would look for something from the HD croud, to bolt to the tripple tree. Or something like bar back? ( whatever they are called) adapters used to move bars back that bolt to the 7/8 tripple & allow 1' at the adapter