So I have a stock 67 Barracuda with an 8-3/4" housing and some old station wagon gears in it. I want to get a real set of posi gears in it but don't know if I should run 3:23 or 3:55 gears. I'm not racing it at all just mild highway cruising. It has a mild 273 engine/4bbl and 904 trans. I do...