"The Same Song" is the classic LP, "Unconquered People" is the follow-up (I've only heard a couple of tracks from this).
"Why You So Craven" is an early '80s Henry 'Junjo' Lawes production with his distinctive early dancehall sound. It's a very good record with the title track and "Jah Is The Way" (both sung by Apple, my favourite IV composer) being exceptionally killer tracks. Their vocals had became more 'mature' by now in contradiction with the amateurish, slightly off-key harmonies of "Same Song" (which are actually considered one of their debut's virtues
Israel Vibration then disbanded only to re-group with the help of RAS records' Dr. Dread in the late '80s. From their subsequent records, "Forever" (from 1991) is the best of the ones I've heard (especially the Apple-penned tunes).