Anybody on here experience of such units, or a build or three I can read about using and mounting them, thinking about one for my car.

What do you need to know? I run a chain diff on the Riot.

I've had them years. In 2 radicals and the Jedi. Strong units!

Just after a few pictures of how you have mounted them, distance from engine to unit, also do you move diff to tension chain or run a chain tensioner

I use shims.but some have tensioners.
I've not got any pics of the Jedi but look at empire racing cars gallery of how bill Chaplin mounts them. The Jedi and radical have a decent distance between front and rear sprockets but the empires are very close as you'll see

https://www.facebook.com/Empireracingcars/?ref=ts&fref=ts

http://www.westwalestrikeshack.co.uk/chain-drive-differentials.php

Bit of info on here

Here's a couple of the Riot that I have on my phone, not quite as good as what will be on the Jedi ;-) but not had any issue to date, except it's quite a short chain run so have to run a little slack (10-15mm).