The only low tension oil rings I ever ran on the street--spotted up the back of my white Super B and it got rid of some oil--Ran great but...
Does seem that you have worked hard and thought about it --the bore scope is a great tool and easy as pie to use--borrow one and try that...on the other hand every Hemi I have ever done used some oil one way or the other--Oil has NO octane so pinging is the tell on this one--I think it is getting in from the top either seals or plug tubes--you have done the intake twice --I bet you that it is OK
Good luck