Des I will have the short block out of my delivery available later this year, I'm replacing it with a 327 but want to keep the top end off the 283 to keep the 327 looking correct. It's an original 1957 548 block with no side mounts stamped FC for 4bbl PG. It's always run a little warm in traffic on hot days, perhaps bored too far (40 thou if I recall) but it's not ever let me down. It's done about 10,000 miles since rebuild (20 odd years ago now).
Just realised I never got back to you. John found one here in Melbourne and picked it up a few months back. He did a deal with a friend of a friend and got the complete motor with 4 bbl and air cleaner.
However johnonetrillion asked about yours - and that's why I dug up this old post. If yours is still available, please let me know and pass on some contact details.