Yes. It will *definitely* increase your distance to switch to a four-finger grip. I was in exactly your circumstances.. I started playing using a three-finger grip, with the pinky tucked under. From someone's recommendation, I tried switching to a four-finger grip.. and immediately gained almost precisely 20ft. of distance on every throw. I did have a few extra grip-locked drives right after switching, though.. it took a little getting used to. But afterwards I've found a four-finger grip is considerably more accurate than my old three-finger one, as well.
So yes, make the switch. Once you get used to it, you won't regret it.