Guillaume, here is a full rip of "Live Good" from the JA mix:
Besides the difference of the flute, the JA mix of "Live Good" is about 10 seconds longer than the UK mix. Actually about half of the tracks on Marcus Garvey are ten seconds longer on the UK issue, while the other half are 10 seconds longer on the JA issue. The biggest difference in length is "The Invasion" which is about 20 seconds longer on the UK mix.
There are no pitch differences on any of the tracks. I compared each track and it's just when each track fades out that changes the track length.
All in all, though, the mixes are not tremendously different to my ears.