I'm debating this same issue on my '46 half-ton right now. I just finished redoing the entire suspension on a '67 Dodge pickup. Rebuilt straight axle (new kingpins, leaf spring bushings, shackles, etc). I also added power disc brakes and power steering. Frankly, even after all that I'm a little disappointed in the way the truck handles. I was hoping for something I could just jump in and drive, and it still drives like a 51-year old truck (perhaps my expectations were too high). In retrospect I wish I would have just done a front clip or MII crossmember. My plan for the '46 had been to keep the straight axle and just upgrade to either discs or Bendix brakes (I have a complete front axle off a '59 to rob of spindles and brake parts), but now I'm concerned that I'll be similarly disappointed in the '46 after the work. For nearly the same money I could do an MII...
