If you were only going to lock one end or the other the front would be your best choice since it is an open diff. The rear limited slip can be manipulated with a slight application of the E brake. Of course optimally lockers front and rear is the ideal set up for off road.

I had an old military instructer that when confronted with a question on how something worked that he had no answer would always answer "AM/FM"...
"Amazing Miracles and F'n Magic"!