We frankly wouldn't drive an A-body over 40 mph with the 9-inch drums, for reasons having nothing to do with the brakes. The small ball-joint-to- knuckle bolts, which are loaded in shear, are known to snap, usually at the most inopportune time."
Well, I used run my Valiant where the speed-o-meter would be straight down and my car would start seriouly wobling(spelling) and scare the living crap out of me.