For anyone that has an interest in oil filters...

[737Driver]

Rick,
In regards to when the embossing stopped, I believe NCRS doesn't have that pinpointed. I have judged chassis on the Regional and National level and I can tell you that because of the lack of specific info, I have given late 69 model year cars with the lack of embossing full credit, that is to say it could have been late 69 or early 70. To muddy the waters further, it seems there is blurry data to support the embossed version was EVER used. With that being said, NCRS does expect to see, currently, embossed in model year 1969 (after the PF-29 cutoff time period) and unembossed sometime(?) in model year 1970.
I know...clear as mud. Hopefully more specific data will be obtained to clear things up.
Regards,
Mark

[Mr70]

That's good to know.
Just to add & I realize you're talking Corvette,..Charley's March,1970 3rd week assembled Z28 came with an embossed oil filter on the line.

Below is what Charley found on his unrestored survivor 70-Z with the undercoating applied after delivery later on.