Analyze My Timeslip

Dumb question. How does a 67 dart weigh even remotely close to 3800 pounds.? It appears to not have a cage/ rollbar?
Reason i ask, my all steel 69 Dart with rollbar, Full carpeted interior, etc, etc missing only the back seat, weighs 3310 with a full tank of fuel and my 320 pound butt in it...lol
If i had to guess, i would think it is all street equipment. If i take off the full street exhaust, and change my steelies (i notice he's got cragars, not the lightest of wheels) with street tires , to race wheels and slicks, i can take 150+lbs off the car