The Aerostar never had a 3.8 liter. It had a 4.0 or a 3.0. So maybe you need to improve the question.
Yes it will "fit" but the re-wirng problems are very complicated.
1996 Taurus never equipped w/ 4 wheel drive
WHEN PUT IN GEAR KILLS ENGINE IF NO BRAKE APPLIED IT WILL DRIVE BUT IF STOPPED DIES
The 2003 Ford Taurus has a V6 engine.
The 2012 Ford Taurus has a V6 engine.
The 2011 Ford Taurus has a V6 engine.
The 2004 Ford Taurus has a V6 engine.
The 2013 Ford Taurus has a V6 engine.
The 2009 Ford Taurus has a V6 engine.
The 2002 Ford Taurus has a V6 engine.
The 2014 Ford Taurus has a V6 engine.
The 2007 Ford Taurus has a V6 engine.