Below is some dimensional data, although I was unable to find the ones online I was looking for. Those have the exact dimensions from subframe mount to subframe mount and the dimensions from mounting point to mounting point on each subframe.

Anyway, you need an experienced frame person to determine what is actually wrong. From the impact I would suspect suspension components first.
Possibly a bend to the front mount of the tie bar at the subframe may be likely from an impact?

http://www.minimania.com/web/SCatago...6/ArticleV.cfm

http://www.minimania.com/web/SCatago...8/ArticleV.cfm