OK, we all know the early 1969 Camaros had a lot of differences, then the ones built after Dec/Jan timeframe. Mainly a bunch of 68 "looking" holdovers of design.
I think I have found another. This is the 4 blade fan from my Oct 68 build's 327 original engine. I did not think too much of it. But when I looked closer, I realized it looks like a 67-68 fan, but has the holes drilled for the larger 69 bolt circle.
In the 2nd pic, you can see where the hole is a lot closer to the rivet than the 67-68 version. Same exact size, both have a stamped "2" on the back of the blades.
Thoughts?
For others: the difference that Kevin is alluding to is whether the reinforcing ribs go to the center locating hole.
The 3927791 fan that is in the cooling article is from an 11C car, fwiw. https://www.camaros.org/coolingsystems.shtml
There's a change in the clutched fans. Wouldn't be surprising to see a similar changed in the fixed fans, though I don't recall seeing other part #'s.