The spacers change the backspace about an inch outward. No big deal there.
The sppacers got a bad reputation years ago. The instructions plainly state "mount flush to the drum surface" yet so many would ignore the interfearence of balancing weights welded on the brake drums. Maybe they didn't have a grinder to remove a small portion of the weights. Anyway...
If the adapters are properly installed they are fine for normal street driving duty.
