I have on my hands an engine from a 2005 X5 4.8is with 635 miles!.. I tried to implant it into my 2004 545i but got stuck at the emission system which is totally different .. a long story short.. I stopped that transplant project... very disappointed.. but. ANYWAAAY..

I am about to buy a 2001 X5 4.4 and tada! want to consider this transplant again...

Is is do-able? Are there too many differences? What are the potential hurdles? What else do I need to purchase?

Thanks...

and!.. how much can I expect to sell that 129k miles 4.4 engine with allegedly no known problems?

Thanks!