Driveshaft orientation, '72 Duster 4 speed
I would put the step down (3" to 2 1/2") to the back.
2nd down from the top here, black 727 shaft with the green tape on the rear knuckle > has the step down at the rear.
Most of the other 904 shafts have the step downs at the rear.
Very bottom shaft has step downs (2 1/2") front and rear, with a 3" main tube center section.
☆☆☆☆☆
I would put the step down (3" to 2 1/2") to the back.
2nd down from the top here, black 727 shaft with the green tape on the rear knuckle > has the step down at the rear.
Most of the other 904 shafts have the step downs at the rear.
Very bottom shaft has step downs (2 1/2") front and rear, with a 3" main tube center section.
☆☆☆☆☆