The articles probably point toward the '86-93 Mustang because it provides the most complete or usable package. Especially if you're after an HO engine.
You can find HO engines in FOX/MN12 TBirds, Cougars, LTD's and Mark VII's. Not sure when the Lincoln went to mass air. They were speed density longer than the Mustang was.
Crown Vic's/Grand Marc's had EFI 5.0's but they were all speed density and non HO (except for maybe the police cars).
The wiring harness from the Mustang's seem better suited for the swap. But the others can certianly work as is or be reduced of un-wanted circuits.
Guess it depends on what you want to start with and what you want to end up with. If you aren't planning a bunch of bolt on's and would be happy with a stock 5.0, the speed density systems are much more plentiful. At least in the yards near me.
I've got a link on my work computer where a guy used a Crown Vic as his donor for a '50's Ford truck. If I remember, I'll post that tomorrow.