In order to drive my '50 3/4-ton at highway speeds, is it possible to simply(?) swap the entire rear-end with an 8-lug '79 3/4 ton chevy rear end with a 3:73 gear. This would seem to be the simplest way to improve speed and update the brakes. I have also read that the guts from a 67-72 C20 rear-end will bolt right in to my existing differential. Is this true?