Read this thread completely:
Swapping out a V1702 IDI (indirect injection) to a V2203 DI (direct injection) in a 743 Bobcat is much easier than swapping those out in a tractor.
http://www.orangetractortalks.com/forums/showthread.php?t=27513
NOTE: There is 4 distinctly different V2203's that were produced, and then there were variations within those models.
Some V2203's are IDI, these are rare, I've never seen one in person.
The V2203's have some differences in the Fuel injector lines between versions, which will make it hard or impossible to use the stock intake on some.
You will need to make sure it has the right fuel cam in it to drive the hydraulic pump gear.
You will need to swap the front cover, and have the bell housing machined to fit the V2203.
You will need to drill the dip stick hole, and if you want the mechanical lift pump, you will need to drill that too, or use an electric.