Does anyone know the size of the bolts for the outer primary on a 1980 FXWG?

I pulled it today and noticed that there was one of the lower bolts missing. It's a stainless allen capscrew and I guess I should order a set of now ones for when I put it back on....

Manual just specs torque but not the actual fastener dimensions.

Thanks for all advice....

 

1/4 -20

 

This might help:
http://www.docshd.com/OEMpartfinder....170529-H100175

 

Use this chart as there's a couple different lengths on those.

 

That's great - just what I needed!

Thanks guys.