steering and handeling help, 73 duster

I am running a 215 65 15 on a 7 in wide wheel with 3.5 in backspacing and am having trouble keeping it from rubbing on the fenders of my 73 duster so be careful that you have the spacing right to pull the front tires in enough for fender clearance if your going overly wide.
Also I am having similar issues with handling and am currently (car in pieces right now) replacing the worn out lca bushings with poly and strut bushings with new moog ones
I am wondering how important it is to box the lower control arms to help handling in general?