New to me Barracuda with Mopar Crate 390hp low oil pressure

With the sensor in that position it may read a bit toward the low side. As it is at the end of the oil galley.
If your filter adapter has a plug in it try applying a mechanical gauge there it may be more of a true reading.
Filters can make a difference, try a different filter, I use WIX non racing filters - no issues
Good luck

Im not using a filter adaptor. Later on I want to do an oil filter relocation.

It had a short Fram filter in the stock location. I used a short Purolator premium filter.