The suspensions, frames, and some body components are very different from the '63-'66. The frame and suspension use a completely different design, with the '60-'62 using a tortion bar suspension and a X braced frame. Front suspension components are somewhat difficult and expensive to get. There's also little or no aftermarket support for upgrades, like disk brakes. As to the bodu, it's mainly sheetmetal diffences. The '60-'61 use a different hood, and the cab is '60-'63.
