I just completed the referee process at Miramar College in San Diego. What it boils down to is matching the specs from the donor vehicle to your current vehicle. What I mean is that is has to have all the same parts, from a newer model and similar weight class. My 5.7 came from a 1992 full size blazer. On the first visit the guy noted my cat was not correct and my air cleaner was missing parts.
The guy was very cool and printed me pages from the reference book they use. I was able to get the air cleaner parts from a junk yard and ponied up the cash for a genuine cat at a muffler shop.
I passed the second time withn no problems. All in all the most difficult part of the process was the scheduling because its done through a California agency staffed by clowns and they need to know you are there for an engine swap. Also be aware that it takes a double appointment so bring a book because you will be there for a couple of hours.
David