8-3/4 should be fine in a lite Dart...it'll just be spinning tires. THEN when it breaks, you can get the Dana.
I beat my fine spline 4-speed,8-3/4 340 Dart and nothing broke. Even side stepping the clutch.
And when it had slicks on it, it would bog but not spin the tires. In fact, that 8-3/4...