A totally naked body in white '69 Barracuda weighs 461 lbs. That's 186 lbs at each forward spring hanger plus 89 lbs at the front end. I weighed it on an ordinary bathroom scale at these 3 points, deducting the weight of the yellow tubing of course. This figure includes paint, some road grime, and factory partial undercoating at just the rear wheels. (Also 1 wheel opening molding shown in the photo that was the very last piece to come off due to a stuck screw.)

I'd think a totally naked body in white '68 Dart should be close to the same.