I use iTunes 7.5 and there is no option to set a gap in playback. There is crossfade which does the opposite if you engage it. I also see no option to add silence in iTunes when ripping. I own no mobile devices so I can't check there but unless they introduced something for a few versions and then removed it again you may be mistaken as to it being a feature.
I normally use XLD to rip and I believe having silences is configurable.
The thing that was in iTunes was user-set gapless playback. http://www.mcelhearn.com/what-is-the-gapless-playback-tag-in-itunes-for/ Sept 2016 - https://discussions.apple.com/thread/7686893?answerId=30721787022#30721787022 - "That option did not make an album gapless. The ONLY thing that tag did was to not cross fade songs if cross fade and shuffle was enabled and consecutive songs from a gapless album were played." So for your purposes it didn't do anything to add a gap, only not remove it, and then only if you had a no-gap album not set as gapless (I think that confuses even me 😉 ).