Topic: What's the diameter of the passenger footpeg mounting hole on a cb550k?

[RFogelsong]

I need new passenger footpegs.  I'm gonna get some off ebay and I've seen descriptions listing footpegs with "built in 10 mm studs" and "built in 12 mm studs".  Which one of these will work for a 1975 cb550k?  The bike's in a barn 100 miles up the road and I'd like to have them in when I get home for thanksgiving in a few days.  Thanks