Welcome to the club of "WTF??". I've never owned a car where it was so damn hard to tell which oil filter I needed to use. :-)
In the end, if you sitck with ACDelco and use PF63E, you should be fine. Personally, I've read a lot of bad things about the new "E" (aka "e-core") filters and would rather stay away from them - but finding the correct-spec alternate brand isn't easy. So many places will cross-reference to an oil filter with incorrect bypass ratings. Apparently, GM changed the bypass spec a few years after the car came out, which is why you can't trust cross-reference charts - a lot of them still cross-reference to filters with the old bypass spec.
The original PF63 oil filters had a differernt bypass spec than the newer PF63E filters. PF63E have the "new" correct bypass spec.
If you do some searches on the forum for PF63, you'll find some interesting posts and debates on all of this. :-)
LMAO club WTF it is!
And yes I had read about the E ahead of buying a filter so was avoiding that one [emoji16]