There are very minimal changes between LS/LT and LV Focus XR5 models so, for the most part, there isnt much to worry about.
We recently swapped an engine out of a very late LT (early 2008) into a very early LV (late 2008) and it genuinely was plug and play.
The only minor issues were stealing a couple of small parts from the dead engine as our new one came from a crash damaged car.