shift knob rethread?
 

Has anyone ever tried to put a m10x1.5 knob on an 86? I was thinking you would have to drill it out to m12 and rethread to 1.25, but i'm not sure how well it would work or if there's a better solution.

The better option is to thread the m12 tap into the m10 threads. Drilling and retapping might not leave enough material for it.

They don’t sell an adapter for that?