72 Duster build - Pro touring slant six

Thanks! Tires are 275/35/18 all the way around and the backspace is 6.25" front and 5.25 rear. The fronts might be a little different as the brake kit pushes the track width out another 3/16" and I had to roll the fender lips and do some minor trimming at the corners. The rears took some trimming too, about 1/2" off the lips and I kinda wish I added another 1/8" of backspace as they stick out just a tad further than I thought they would. But I'm still very happy with the fitment.

Do you think another 3mm of positive offset (1/8” more backspacing) would have been enough to avoid rolling the fender lip? And was the trimming at the corners on the top of the fender or at the bottom corner?