[QUOTE
Originally Posted by
Andrew F 
The GB's on the left are 13/32 with the sleeve for the chain but no index hole
Is the purpose of the sleeve just to give additional support to the index chain? Can a regular wing nut be used on the drive side of a SA hub?
][/QUOTE]
Yep, it supports the chain, keeping it off the threads. I don't think a "regular" wingnut would not be deep enough, though you could machine and thread a sleeve, might be easier to hunt up the correct nut.