I finally got the 39 on the road back in July after a full frame off build and I now have about 400 miles on it. From the start I always had a vibration at freeway speed. I havent done much freeway driving lately but I decided to take a longer cruise yesterday. The vibration was still there. Today I decided to check things out. I figured maybe I didnt get one of the wheel bearings seated correctly. First up I checked the drivers side and everything seemed tight so I jacked up the passenger side and there was the movement. I thought OK just need to tighten up the spindle nut a bit. Popped the dust cover and found that the bearing was fine. I finally had my son shake the tire while I was underneath. I found that the top A arm bolt was loose. Now I know I tightened everything up upon initial installation but upon further inspection I found several loose nuts on the suspension. All areas that were loose were areas where rubber or poly bushings were used. I wonder if things loosened up as the bushing compressed or relaxed from use. Any way after tightening no more vibration. Im darn glad I didnt just pass it off as a tire that was a bit out of balance.

1939 GMC Resto-Rod