Trying to ID the gear set in my 833

I was trying to ID the gear set in my 833 using the info on Brewers web site. Now I'm confused. His site shows that gear sets are identified by the number of grooves cut into the gears and the cluster gear shaft. What I'm seeing doesn't make sense. I have 2 grooves on the gears, indicating a gear set for an 18 spline 4sp and no grooves on the cluster gear shaft. There may be grooves on the cluster, but they are so light that they appear to be tool marks.
Compare my pics to the pics on Brewers, it's under the "Before You Order" section.
My trans is a 23 spline that was made July 14, 1969. I can count the gear teeth, but I still would like to figure out what's going on with the markings.
Thanks!

The reference grooves apply to the gears, not the syncro assy. Your trans is 2.66 low gear. Should you have questions like this just shoot us an email.

This is my first 4sp rebuild and I'm glad to have an experienced eye available. Thanks 64dodge572.