Might get lucky and find one at a junkyard. You can also get custom, and just 3D print one or else snag a nice washer and nut, or flanged nut combo that looks fine. I believe it's a 8mmx1.25 thread, but I haven't had an engine cover hiding that sweet boost-maker since ~2003.
Thanks, but I think I might have discovered a factory replacement nut for it. I was checking junkyards locally but they only have the covers and not the nuts. Also raided my washer/nut collection but nothing seemed to fit just right. Plus I was hoping for an OEM part to keep it stock, hopefully what I just found will work. I appreciate the advice anyway.
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