I've done one on my 63. The part that needs changed is the inner panel in the rear of the cab. The window opening is the only thing needed changed on the outside. All you do is cut out the hole bigger. On the inside, you will need to drill all of the spot welds holding the inner panel to the cab and cut it from the roof panel. Swap it out with a rear panel from a big window cab (which I have one) and you're done. If you're interested in my panel, PM me and we'll talk,
Scott
