What I know: A specific pan must be used. FMS (and others) sells a 351w/Fox swap pan and pickup tube. (A "truck" 351w pan won't work.) Last time I checked, the FMS one was about $175.00.
What I've heard: Some Crown Vics came with the 351w. (Police package?) Supposedly, that pan and pickup will work in our cars.
I hope this helps.