I don't think that will work for the 60-62 chassis which is different than the 63 and later chassis'. The info I've gathered over the past few years is that suspension upgrades/changes for 60-62 require fabrication. To me that means skill or money, both of which I don't have enough of. Just because I've heard and read this, doesn't mean it's true. If and when you find out for certain, let us know!!!
That being said, I really like the torsion bar suspension. Word is that they stopped using it to save money. You can adjust ride height in minutes and the ride quality is GREAT w/ new shocks/radials and all parts in good order. My 62 gives a better ride than my friends new Ford. And he admits it.
Last but not least, CPP(Classic Perfomance Products) offers a disc kit for your truck.
http://www.classicperform.com/6092chevtrk.htm