Before anyone cuts a hole in a boat that was primarilly designed to have whacker power, you might want to take some basic measurements and make sure a jet install will even work. It is possible that because the motor sits lower in a jet install compared to an I/O setup, the engine might not physically clear the tunnels etc.
I'm for the most part what you would call a jet guy, but that hull is a proven setup with a whacker. You might be better off selling the 460 and JC and finding a used outboard setup to run in it.
My first step would be to talk to the guys at Lavey, and see if they even offered the boat as an I/O and if so, did they ever do any jet drive installs.
Chris