NOS PF-25 Oil Filter

[Ls6 Ragtop]

Hi Rich,
The embossing on the PF25's was only on pre 71 dated filters to my knowledge.

Also to the best of my knowledge, PF25's were blue starting in late 73 or early 74 timeframe?

What you have with the 89 dated boxes look like the re-screened filters that were being done in the 90's and through the early 2000's by a few sources for restoration parts.
I know a guy in CA that supplies restoration parts that made quite a few runs of these back then. They are actual AC Delco parts so they are high quality pieces just not from the 70's which isn't necessarily a bad thing as I'd feel more comfortable using these on a car that's being driven as the filter elements aren't 40+ years old.

I don't have any of these re-screened filters left in stock to compare the underside for you unfortunately.
I do have a case of 72 dated filters in stock but I don't see any markings there to help identify them. My 70 embossed filters are stamped AC on the bottom near one of the 5 outer flow holes.
The thing to me that makes me think with pretty good certainty what your filters are, besides the box, is the finish on them. The original white finish was fairly glossy and the screening was no where near as perfect as the ones that my contact in CA was supplying along with his having mat white finish on the filter itself and near perfect printing.
Maybe somebody else can help us out with more or better info.
Chris