Chain box nuts

[dlr308]

1979 911sc.
I am just reinstalling my chain boxes.
I thought I did a good job taking lots of pictures. Apparently not enough!
On the right side chain box I have 5 nuts to attach (2 internal and 3 external).
4 of the nuts are regular M8 (R in the image). The odd nut is M8 thread but has a different shape (L in the image).
I cannot figure out where this odd nut goes or why it is different in shape.
Does anyone have any clues for me?

Thanks, David

[Flat6pac]

The one on the left is the top nut that supports the A/C table.
On the inside you need waved washers and regular nuts.
On the outside a steel washer and a nyloc
No washer on the left nut in the picture
If you’re removing the AC compressor then use a regular nyloc nut
Bruce

[dlr308]

Hi Bruce - perfect.
Thanks very much - A/C gone, so nyloc it is.

d