Well I don't know much about it, but my buddy put a 302 in a V6 86 notch, and didn't HAVE to change any suspension. He put in traction bars, springs and subs just for the hell of it. As far as my humble self knows, I haven't heard of any necessary suspension mods.
Good luck
------------------
Elisha (Mustang Chick Extraordinaire)
1994 GT/Saleen: Cartech intake,4.10s, full exhaust, pulleys, Compucar nitrous kit 125 shot
Sold the 1986 LX sedan
http://www.geocities.com/mustangbelle_306
AOL name: GT306Chick