The PAL & NTSC versions have the same framecount, but to make the NTSC audio match the PAL playback you have to speed it up by 4.096%, a drawback is that this also increases the pitch, I tried timestreching the audio with a few different 'main' audio editing applications to preserve the pitch but it introduced glitches into the audio, not noticable on speech but with orchestral music you can hear them, which I wasn't happy with so I left it with the slightly higher pitch.
In the case of my ANH, the NTSC version runs for 2:01:18 and the PAL runs 1:56:06.