IMOHO, the springs and shocks are at about th right setting, especially th rears.
(Depending on who you ask) My front 425# coilovers are either 850# or 1700# (2x or 4x). And I still barely lift the front tire. That could be solved with 50# heavier rear spring, and I am only running 350# rears (soft).
See this link for a series of photos:
http://www.dariusrudis.com/mustang/svtoa/
I would try playing with rear panhard height. IMOHO, its the roll center of he rear that is producing the front to roll over on itself.