Vibration at 75mph. Bad hub?

I can't seem to get my car to go past 75mph (not that its really necessary) anymore without a pretty decent vibration. I've been noticing a weird sound when I take sharp right hand turns. Almost like something is loose in the suspension. Sounds like a light clunking sound. I jacked the car up and nothing in the suspension seems loose. I did a suspension rebuild about 3 years ago and it's never given me problems. I can also kind of hear a "whomp whomp whomp" as I'm driving in a straight line. This is on a 71 Duster with 9" drums.

I went and bought new inner bushings, races and seals this weekend. I looked down in the hub and they are a little different than 67 9" drums. Inside the hub, the race buts right up against the lip on a 67. On my 71, the race sits about 3/8" above the lip. One thing I noticed is there is less of a lip on one side, almost like the hub has been rounded out. Both hubs are exactly the same so I'm not quite sure if its just the casting or what. Either way it's my only mode of transportation so I had to install the bearings and get on the road. The bearings didn't fix the problems I've been having so I'm guessing its either the drums or something else. What do you guys think?