Hi fellas, I've got a 2 piece tail shaft that came with some stuff I got but I dont know if its v6 or 4cyl.  Is there any way to identify it?  Maybe by length or diameter?

My 1600 had a single piece shaft the 2l motor that I brought came with a 2 piece shaft but it was from an imported mk3.

I thought they were a v6 only item but my parts book lists a 2 piece for 4cyl models as well so I'm not sure what was done back then.
 
Another question, my v6 was converted to a single by previous owners and I have seen this done a lot.  What was the problem with the 2 piece?  I guess ford engineers had a good reason for designing it with a centre bearing are so many changed over.

I've got two versions of the two piece tailshaft in my shed.
 
The V6 one from what I can tell has a different mounting flange where it bolts onto the diff (full circle which maximises strength).
The other one I have which I assume is from a 4 cyl is square shaped where it bolts to the diff meaning there is less metal/material. From memory either the yoke is smaller on the 4 cyl shaft or the shaft diameter is smaller or both.
 
The CV joint case/housing on my v6 shaft was pitted and grooved which made it clunky. I haven't been able to source a new replacement which is probably why one piece shafts have been used.

The flange is round so thats promising.  But its not a CV joint, its a bearing behind a uni joint.  My parts book shows bearing with uni joint, my Ford manual describes that setup but also shows a pic of a CV joint (ie no uni joint)
 
Motomobil show both CV type and uni joint type and also list bearings and rubbers.