[Huck]

If you have your hardtop on, body flex should be a minimum with solid rocker/torque boxes and good rocker panels assuming you have decent body to chassis rubber mounts. With the top off, all bets are off as Chevy had body flex problems and had to reinforce the door latches for just the problem you are having. Even perfect boxes, rubber mounts, and shimming, you can still get some body flex with the top off so don't expect too much ---just enjoy it as part of the Classic ride! hehehehe