Posi needed!! Please help

So I found a sure grip that I wanna get but is there anything I should know first? It's a clutch style and a 30 spline unit. I also want to put new gears in it cause as of now I am running the stock gears, I believe they are 2.76's or somewhere around there. I was wondering what gear you guys think would be good? I drive to the coast a lot during the summer so I don't want anything too short. I use to have 3.91's and it was a nightmare above 50 mph. I was thinking 3.23's, what do you think? Thanks -kory