Here are some pics to help explain what on earth I'm on about here.... I raised the diff up 0.8mm as an experiment and the issue is resolved but I am not happy that I need to do this.
I will build up the final drive but I can see it will be quite hard to check if it's within tolerance or not (final drive to pinion) as I can't really see where they mate up.
I lifted the outer diff bearing shell up 0.8mm (checked with feelers) in the casing and the speed drive clears OK - as per pics.
I'd be happy to shim properly if I fully understood why and the full consequences but it just should not be needed. Some oddball case I've got? Who knows !
So - here's the list:
Quaife on the left Standard on the Right. Both speedo rings seem to be at same height but it's quite hard to tell. ( I measured but need a better method as need to be <1mm accuracy)
This is where they go: See speedo pinion and bearing outer bearing shell
Now - I nudged up the outer bearing shell by 0.8mm as shown here:
And the result is that for LSD the pinion JUST clears - you can see how close it must be even without this 'problem' - the body of the LSD overhangs. Right bu66er to get that pic!
And here's a the standard Diff ; bags of clearance regardless really as the body is way smaller