.................. two years on from the last post here's something to get you going on this!
In starting off the post mab01uk says that the 4WD system was taken from an Ant that was used at Abingdon to tow non-starters off the end of the MG line. That fact I've found elsewhere on the internet and even in a book about rallycross Minis so it looks to have been a generally agreed fact. However in the light of what I've found out recently I don't think that the 4WD system did come from an Ant, I think that it came from a 4WD Moke made earlier in the 1960s in the Longbridge experimental workshop. Yes, they DID make a few 4WD Mokes (i.e. one engine driving all four wheels as opposed to the Twini Moke that had two engines in order to drive all four wheels.)!
There's a logic to it if you think about it. The rear end of an Ant and the rear end of a Mini Clubman are different. The Ant was never a Mini and the Mini never an Ant. Therefore if they had tried to swop the parts over from the Ant to the Clubman it wouldn't have been easy. Remember too that Special Tuning were in a hurry to get the 4WD Clubman out to compete with the 4WD Fords. However the rear end of a Moke was essentially the same as the rear end of a Clubman so the swop would have been relatively easy.
If anyone has a photo of the rear diff of an Ant you will see that it is different from the rear diff of the 4WD Clubman. (See Clubman photo posted at the beginning of this thread.)
I'd be interested if anyone has any comments. Am I right, or am I way off the mark?