Jamie Hiscoe, an Ontario chapter member, has done this with his 94 V6 car. On a Fox-chassis Mustang, the 3.8 will bolt up to either a 2.3L 4-cyl. crossmember, or a 5.0L V8 crossmember, with the correct engine mounts (using 83 - 86 3.8 Mustang mounts I would think). So it could be done, I had pondered this swap myself if I could find a clean ragtop Fox Mustang. Just think, all the torque of an SC motor in a car weighing about 600 or 700 lbs. less, and it has room for a proper exhaust system !!
Jamie goes by the board name "V6Sprout" ... so you can try sending him a private message, or just posting a question on the SCCoO chapter forum if he doesn't see this thread.
cheers
Ed Nicholson
SCCoO