Date Code?

[68z302]

I had this question posted at camaros.net with no answer of any kind.
Were brake calipers date coded?

I took apart front disk brake/A-arm assemblies from a supposed '69 Z28 wrecked in 1970. Yeah, I thought that too till I saw them.
These are "virgin" calipers that have never been rebuilt & the rotors are thick enough to look like they've never been turned.

There is a single number '9' cast into each caliper that looks like it could be a date code?

The single number '9' is made in the casting by what looks like a replaceable die (you can see a slotted screw impression) just like a date code would be.
I have seen Julian date codes & it's not like that, it's cast not stamped. It's more like what would be on a water pump without the Month letter & day number just a '9' on the end (blank, blank, 9).

It could be a 6?

I heard that 69 calipers are supposed to be "V back".
I don't know what other years had that shape on them. Most GM calipers look similar except the hose location is in different places.
These calipers have that "V back" 2 "v" notches in a rectangular bar that keeps the brake line's square brass block from rotating.
GM dated coded most of the cast components so wouldn’t this make sense?

How about you guys with judging know how , would this "date" count for points?

They also have the number 22 stamped into each of them on the bottom edges.

Are there tons of these around?

I could post a pic if anyone's interested but I don’t have the software to resize it, or maybe I’ll just link a picture later.
Thanks in advance.