Kick Down Lever

Well when I bought my 68 Nova. The guy told me that the kick down lever was not hooked up. But he never told me what it does or what its for. So I have no clue. Its easy to hook up. But is it really nesscary or should I just leave it alone. Becuase I mean the car runs fine. I would really like to know what its for though. The Tranny is a PowerGlide.

The kickdown cable is more properly called the throttle valve cable. It alters the transmission shift points. shifting at a higher speed with increasing throttle opening (and shifting sooner when you featherfoot it). The procedure for hooking it up and adjusting it is in most service maunals.