They quit equipping new cars with bias ply in 75. I figure they rode on new radials and smaller bars for the 75 MY. They probably realized that they needed a bigger bar for radials and came out with the .85 in ‘76.
Is this plausible, @junkyardhero ? I’m hypothesizing the increase in bar sizes correlating to radial use.
anything is possible. the more *likely* scenario is ma mopar trying to save a nickle and doing away with the smaller .830 and just equipping all the slant cars with .850