How much will one of these axles cost. Has anyone done this swap? I have a '73 Blazer with a stock 12 bolt. I need at least a limited slip differential and a set of gears. I am trying to decide if I should build the 12 bolt or swap in a 6-lug 14-bolt. I have 33" tires now but I plan move up to 35s. I won't go any larger than that.