I have a lexus es300 am about to do a engine swap. I found a engine at lkq with 87k miles. Should I take off any parts from the old engine for back up like the starter, alternator, etc? Should I replace any parts on the new engine since it's out of the car?

 

Timing belt, my 2004 ES330 V6 recommended change at 90,000. I bought a kit with a water pump included. I did not do the job myself, I have a trusted shop I use for the things I don't want to do. My age and physical condition are limiting factors in what I am willing to do these days.