Sorry to barge in, but you still have your data wrong.
It was Ramses II, who reigned 67 years.
And Pepi II's last attested Biennial Cattle Count is not the 33rd anymore but the year after the 31st count, meaning that he reigned at least 63 years.
It is interesting to note here that some scholars such as Von Beckerath already believed Pepi II’s reign-length of 94 years according to Manetho to be likely a misreading of long-lost original texts by early historians, and ascribed him a seemingly more realistic figure of 64 years, which seems more feasible if he was succeeded by his son as Egyptian tradition states, rather than a grandson. Pepi II's highest attested date is the "Year after the 31st Count, 1st Month of Shemu, day 20" from Hatnub graffito No.7, according to Spalinger (Anthony Spalinger, Dated Texts of the Old Kingdom, SAK 21, 1994, p.308). On the Egyptian Biennial Cattle Count dating system, the 31st Count would be equivalent to Pepi II's Year 62, so his last attested date is his Year 63, which comforms well with the suggestion of a 64 year reign for him by Von Beckerath, given the noticeable absence of known dates for Pepi II from his 33rd to 47th Count.
A previous suggestion by Hans Goedicke that the Year of the 33rd Count appears for Pepi II in a royal decree for the mortuary cult of Queen Udjebten was withdrawn by Goedicke in 1988 in favour of a reading of 'the Year of the 24th Count' instead, noted Spalinger (Anthony Spalinger, Dated Texts of the Old Kingdom, SAK 21, 1994, p.308).
So the pharaoh with the longest attested reign is still Ramses II
