I'd have to agree with Sunder on this one.

Take it to a frame shop, have them pop your body loose and tweak your frame to factory measurements.

My 91 had front and rear collisions in it's life, one each were really bad. Each times, I had a regular shop do everything they could to get the body to look like it hadn't been wrecked, and get the frame generally true, then let the frame shop do their stuff. Driving to the frame shop was a learning experience. Everything felt crooked, then from the frame shop, wow, like a new frame. If you start noticing that it seems to be going crooked again, have it retweaked after 6-12 months, depending on how bad it is messed up.

Just my $0.02