Then it is irrelevant like nitrous.
To make any car go faster outside the engines power/power train, its suspension, then weight.
440 Dusters even get lightened. The car is light? So what! It just makes it easier to move no matter the engine. Why does the car have to be at or near full weight to judge the engine. Going fast is going fast.
If someone builds a full weight Duster and runs 12’s with it and then decides to remove 600lbs., then runs 11’s, so what!