Another on the list of songs originally released as edited singles, later reissued at their full length. I can never remember what I think of as the full list, but "She's Gone" and Aerosmith's "Dream On" both come to mind.She's Gone was an even bigger flop when it was first issued as a single, only making it to #60 in the Billboard singles charts in 1974 - it wasn't until 1976 that it was a Top-10 hit after it was re-released on the back of the success of Rich Girl, the single from their album Bigger Than Both of Us from the same year.
(Or maybe the reissued singles weren't unedited, I just happened to only hear the uncut versions on the radio the second time around.)