So when I go to purchase it, it asks me whether I want light, medium, or heavy loads. I understand this has to do with the weight bearing down on the suspension but I want to know what's the limit between each. I'm that light load is stock. I'm only going to get the arb grill guard, k and n air filter, new muffler, 31 wheels and the mopar light bar made for the liberty. Would I still go with the light load?