A muscle that is mostly slow twitch thrives on a rep range of 12-20 or a time under tension of 90-120 seconds. Many muscle groups are a combination of the two. In that case, a middle ground is best. A good time under tension for this composition is 60-90 seconds.
Of course, all sets should be taken to at least muscular failure with some HIT variables added in every second workout. Remember that muscles that are mostly fast twitch will gain the most muscle because that is the fiber type that is most responsible for muscle strength and size. Slow twitch fibers thrive on aerobic or endurance activities but will increase somewhat in size and strength but not anywhere near what fast twitch fibers will.