I don't think your type 9 box/flywheel/clutch etc will just bolt up and work without a fuss - speedo drive etc is something to think about.

Your mk3 Granada DOHC has an auto sump, if you were to use an MT75 RWD manual gearbox to convert the granny to manual you would need a manual sump as the starter motor is on the other side.

But as your going to attempt mixing that into the Sierra with type 9 stuff I think it might be awkward?

Good luck