Nice picture but we need another one with the stock arm to compare.... is the tire going to hit the arm or the frame with the stock arms?? Maybe they just gave it some extra offset, more than needed ???? Dunno....
I agree with yellow73....my larger tires rub just barely on the upper inside frame pocket just above the trailing arm pocket. Nothing serious on the rubbing and all looks good while aligned with 1/8+" clearance but when driving something changes back there and causes some slight rubbing and this is with 18x10 5.5 BS & 275/40/18. I have heard that others have this slight rubbing minor problem too.
The aftermarket offset trailing arms also reposition the emergency brake cable and they are much stronger and rigid than the stock rubbish.
On another note, necessary is spelled as so.
Stock arms are flimsy, if youw eld them all the way through that will help. The aftermarket ones are heavier if I'm not mistaken. They are prime candidates for additional holes