Early GS750 clevis mount bolt size

[hannibal]

I have a pair of Hagon shocks on order from Mark at British Cycle Supply. I'm planning on installing new hardware with the new shocks. The usual trick of reading the part number (09104-10002) doesn't seem to indicate the bolt size used on the lower clevis mount.

Any idea what size this lower bolt is? Is it standard pitch (1.5)?

Also, I usually replace the hardware with stainless steel bits when I'm replacing parts. Is 18-8 stainless OK for this application or should I go with grade 10.9?

[hampshirehog]

M10 1.25 thread (Japanese standard).

[hannibal]

Thank you!