If you have a limited slip rear differential helps tremendously. Regardless, if you don't want to/can't afford to put a new pair of Winter (not All-Season) tires on the rear, a much cheaper and great option is a set of radial "Z" type roller chains. Definitely about 750-900 pounds of sand bags/tubes between the rear axle/tailgate. Put a 2x8" board on edge behind the wheel wells from bed wall to bed wall to prevent the sand bags/tubes from shifting/sliding forward on a panic stop or impact. Stay light on the throttle from stops/while turning and the same with the brakes. Use coasting well in advance to slow to a safe braking speed for a stop light or a turn, don't lock your front tires.