Dad, congrats on making to retirement. I, myself, have 3 1/2 weeks left and frequently tell people who ask, what are you going to do then?, that I have so much to do that I don't have time for a job anymore.

As to your question...of course you can swap a later assembly in but of course there are adjustments that must be made. Mounting points and spring position have to be modified. Also it is more than likely a different width rear so possible wheel change and back spacing has to be considered. Definitately not a direct bolt in.