My '68 was very low early in its life. The factory springs front and rear were terrible. It would bottom out easily, hitting those axle bumpers (and possibly the pinion bumper), especially when I had passengers in the back seat. The sound and shock from the hit was teeth-rattling. At some point one of the bumpers must have been hit so hard that it disappeared.

I tried spacers in the front springs but that made the ride even worse and they got jarred out on Illinois potholes. By the time I put new springs on 31 years ago, I couldn't clear a speed bump without scraping the frame.