1970 Duster 340 automatic trans 741 or 489 raer end case?

Should a 1970 Duster 340 automatic have a 741 or 489 rear end case from the factory ?

I think you would find a 741 case. I have been told by some that they have seen 71 340 A-bodies that had factory installed 741 cases.

My 69 340 Swinger=741
My 71 340 Duster489

1 owner 72 340 Demon, Auto / 3;23 open w/ 741 case

I have never seen anything but a 741 case in an original 1971 340 car.

72 Demon 340 auto 489 sure grip 3.23, 72 Duster Twister /6 3 on the floor 489 sure grip 3.23 if that means anything. But not sure on 70-71

Scott, My Question was in a 1970 ....Does that apply to 1970 as well

My 70 340 4 speed duster- 489 case. My 71 D100 - 741 case.

My 70 340 4sp came with a 741