Torque boxes and frame connectors. When are they required?

crackedback said
If you were to choose between one or the other, boxes or connectors, do the connectors.

Running stock leaf spring location? The rear boxes will help stiffen the area. With a relocation kit, the rear boxes aren't worth the effort. The front boxes with connectors are not worth the effort, IMO.

The boxes do stiffen the unibody, not to the extent a pair of connector will.

On a car with 500HP, do the frame connectors.

Stock leaf spring location. So If I'm getting the connectors there is no point in getting the front boxes. But since I have stock leaf location I could benifit from a set of rear boxes? Or are the frame connectors all I need? I found a set of Hotchkiss frame connectors for $250. No cutting. I'll have to have them welded up when I get my exhaust done or something.