[philinjax]

Boxed trailing arms are like tits on a boar hog, worthless. The stock trailing arm is a strong and rigid piece. Unless you slam sideways into a curb at significant speed, they will retain their shape, boxing the arms will not help in this case. A much more significant concern would be the integrety of the arm to chassis mounting, much more suseptable to distortion than the trailing arms, as such.

Phil