question about boxing a frame.

getting my 42 dodge truck ready for a fatman independent front suspension and a magnum 360. i boxed the front frame rails in from the crossmember under the seat to the front of the frame. is it necessary to box in the center section from the crossmember to the rear. you can see in the picture the part i am talking about. it will be my daily driver and i won't be hammering on it.

Unless you plan on doing drag racing or heavy towing, I wouldn't worry about boxing the rest of the frame. I probably would not have boxed the front part if it was just going to be a driver, Dodge truck frames are a lot tougher then the other truck frames of the same era. Gene