I have heard of one or two stories of the chassis rails being pulled inwards due to the forces being on just the outside of the rail.
No proof though, just hearsay. I can't believe it with no proof to back their claims up, no one can say if this particular design is rated either.
As Inc said, back up the claims. Or at least post a link to back them up.
On another note, if anyone has or sells a suitable rated product, I do not mind if you spam me via PM, god knows I need them.

