and I am especially surprised that triumph props have the same pcd as ford. NOBODY has ever mentioned that before.
You need to tread carefully here Clive.
Ford UK changed from imperial to metric in the early seventies (during the production of the mark 3 Cortina,
I am not sure when that corresponds to in the Capri production).
Triumph in the 70s used at two UJ sizes with corresponding flanges, so used two PCDs.
Dolomites use the smaller size. T2000 used the larger size for the driveshaft (and the smaller on the prop).
A Dolomite prop won't fit a Capri 2.8 diff. (I have just tried)
It is possible that a Dolomite prop could fit a mark 2 Cortina or mark one Escort diff though?
Therefore I am thinking it may be possible to use a mark 2 Cortina diff flange on a very early mark one Capri three litre differential?
Whether a Dolomite flange could fit the Capri diff is another question? I suspect yes.....
The thing is Clive, you are surely going to have a bespoke propshaft anyway?