I've owned my Discovery since 2003. 5 years ago the engine overheated and died. I had antifreeze in the engine. I was told I needed to replace the engine. It's been sitting since. Does it make sense to put in a rebuilt engine as compared to installing a brand new engine? My desire is to get it back up and running and then give it to my boys in a couple of years when they start driving. Any thoughts or recommendations?