One thing people recommending a welded diff for a DD need to consider is that we get a lot of snow up here during the winter. I drove around one snowy winter day with my ARB locked in and let me tell you, it wasn't fun <img src="/forums/images/graemlins/scared.gif" alt="" /> Open diffs are nice in the snow because the 'useless' tire acts as an anchor to keep your truck pointing in one direction. You get both rear tires spinning and rotational torque is much more likely to make the back end try to pass the front... especially in a short wheelbase truck, especially going around turns. IMHO, for a DD 12bolt get an ARB or just leave it open if you live around these parts.