Limited slip is like the old posi-traction. If 1 wheel is on ice, the other side will grab and get you going. Non limited is I'm guessing an open diff where if 1 wheel is on ice and spinning, that's as far as you are going without putting chains on. The electronic locking diff is like an open diff until you switch it to lock, then both wheels will turn, as they are locked together.
Hope that helps. Maybe someone with similar set-up will chime in with ratio ideas. Good luck.
ps. diff ratios are often referred to as lower when the actual numbers are higher and higher when the numbers are lower.
Confusing, but think of it like low gear vs high gear. Low may be 4 to 1 and high may be 1 to 1.
Happy Glamping, Norman & Elna. 2008 Winnebago Adventurer 38J, W24, dozens of small thirsty ponies. Retired after 40 years wrenching on trucks! 2010 Ford Ranger toad with bicycles or KLR 650 in the back. Easy to spot an RVer, they always walk around with a screwdriver or wrench in one hand!