Ron, there may be other sources, but this overseas outfit always comes to mind:
[url]http://www.hard-to-find-parts.de/pd1002759805.htm?defaultVariants=search0_EQ_1 Stück_AND_{EOL}&categoryId=16[/url]
http://www.hard-to-find-parts.de/pi-340115144.htm?categoryId=16I'd also try your local or online Kawasaki parts vendors:
As listed on
http://www.partzilla.com/parts/search/Kawasaki/Motorcycle/1969/H1+Mach+III/CRANKCASE+%28%2769-%2772+H1-A-B-C%29/parts.html172G0875 STUD 8X75 $4.60
Ron Ayers may also be a source, as I've purchased from them as well:
http://www.ronayers.com/STUD-8X75-P3740782.aspxBut with either of these last two, always email them first to check availability, as sometimes certain parts will be backordered.