"Creeque Alley" appears to be a different take in mono. But actually, I seem to like "California Dreamin'" in stereo with the guys in one channel and the gals in the other. They don't make many stereo records like that anymore.
The Mamas and The Papas are one of the very rare acts whose work I much prefer in mono to the rather oddball and uncomfortable stereo mixes. The 45 mixes blast the stereo versions out the water - much more powerful all round.
Long before Fleetwood Mac, the Mamas and the Papas were notorious as a mixed-sex band whose members fooled around with each other. The single version is superior because the vocals are all but buried in the stereo mix.