Engine Swaps

Hey guys...I'm new here.
 
I have a mini sand-rail that currently has a carb-ed Honda late model 600 engine in it.  Runs good, but I'd like to swap it out with either a fuel injected 600RR engine or a 1000RR engine.  With the current mounts, would this be possible without cutting or welding new mounts on the frame?  What special considerations would I need to make to get the fuel injection to work correctly?
 
Thanks for the help!