It looks like those springs have sagged a little from old age and negotiating too many bumps. Look at the distance between the frame and the rubber bump stops. It's going to bottom out on the stops anytime a serious bounce happens. I'd suggest getting the springs re-arched, adding a leaf, or finding some less-tired springs. Chances are the drag link is already out of level due to spring sag, so a lift MIGHT bring it back closer to right. I'd prefer to restore the suspension to its original condition rather than apply a Band-Aid fix.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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