The auto tailshaft won't fit (length issue), but the actual yoke should be fine. I know for a fact that a friend used the yoke off his factory auto MA71 when he did the R154 conversion.
Sometimes yokes can be a bit tricky to get in, as they are supposed to be a very flush fit - not to mention oil tight!!
A light sanding with some very fine sandpaper, as well as a small bit of oil inside and out, should help the job.
But seeing as there are people in here disagreeing with me, I wouldn't mind clarification - in my experience there has been no problem.