Mounts are different, so more than likely not a direct drop in.
According to my info, the bellhousing is also different, so you may need the transmission out of that Mustang too.
You will need the matching ECU and wiring harness too.
If you can overcome all that, it will probably make a nice little candidate. Between Super Six Motorsports and Tom Morana, there is a number of performance options available for the 3.8.