Ok...Fine.
1974 Duster motofied slant 6 = A turd
1974 Duster bone stock 360 = tire burning, slant killer.
That's roughly a 3300 lb car. You need to lose at least 400 lbs,if you want some performance with a slant.
So,lose the bumpers,back seat,passenger seat,carpet,heater,spare tire,radio,door panels,mirrors,and your ready to go !