Patrick's ring set is for a closed drive shaft. I have never owned one, but I have helped build a couple up. SM420's are geared so low that the 3.55 gears probably help them. However, I just can't imagine a 216 having any spunk at 50 in hi gear with 3.55s. But then again, I grew up in the days when pickups sounded like they were going to fly apart and now I guess now I just don't hear them. But I still like to give it the gas at 50 and feel some power.
