A limited slip rear end will not spin you out going around a corner, a spool could have a tendancy to do that if you hung the rear end out a bit but even with a spool it has a tendency to put a push in the front end more than loose on the rear.

For a 60 mph cruise at 2,300 RPM on a 31" tall tire, your rear end gear should be a 3.50:1 ratio.