This might be a stupid question ....

Is a Duratec bellhousing (RWD cable one in particular) the same lenght as the standard Sierra Type 9 bellhousing? Logic seems to say it would be just wondered if the rear of the engine would end in the same place?

Yes it is.
I asked that question of them only the other day as I'm just about to buy. Although I'm buying the hydraulic one but they are both the same.