Land Rover Repair: Swapping trannys, bmw engine, bmw motor

Question
I have a 98 LR Dis. I recently flipped it bout 5 times in a field. I found a 99and 1/2 (as advertised) on Craig's list that claims all it needs is a tranny put in, will mine swap out with it? (if it's still good, motor fired right up after wreck)  Was also told that 98, 99 where the last years that a BMW motor was used, true?

Answer
If the 1999 is a Discovery I the transmission will fit.  If it is a Discovery II (the model that came out mid year) the transmission and engine are both different.

Neither vehicle has a BMW engine.  The BMW 740-derived engine was used in Range Rover models for the 2003-2005 mode years.