Hi Michael
Don't think a sliding joint is needed
When I asked for the quote I had not fully finalised my engine position & asked D&F if it was possible to have one.
I thought that would give me 15-20 mm leeway in either direction.
Oops nearly forgot, it's quite nice to have the option of being able to remove the propshaft without dropping the diff or removing the gearbox
AshG had one made up recently, perhaps he will be along with some advice