Hi my brother changed his 65 b-body k-member and found that you can use a cross member out of a 66-70 b-body four speed car even though it has a 727 auto. everything will line up. He had his drive shaft that came out of the 65 plymouth and it fit back in the car.

1965 plynouth
440/727 10.70 on motor and 9.60 w/150 shot n.o.s