Denny,
you don't have to change anything on the yoke or driveshaft as it bolts right up. I measured the distance from the yoke seat to the housing parting line on mine and between the old and the new there is a difference of 1/4". I have a splined slip joint at the back so this won't be a problem.
The reason that they state that the new gearset only fits into the 67 to 72 pumpkin has to do with internal differences.
