I think her talking about a street truck here, loosing 3 or 4 lbls off the arms will not make any noticable differance. Running it over a pot hole or a rough road will . The arm is a strees member and you don't want it to bend, thats why special trailing arms for Cameros and Mustangs are boxed for added performance. if you look at one of these arms, it's just two pieces of stamped steel that are rivited together. That plated the 20 and 30 arms becuse more strength was needed and to holed them together better. you can loose a lot more weigth somewhere else and you can improve the handling with springs, shocks, and sway bars. It's a bad idea to drill these arms. If you want lighter arms, spend the cash and go with a 4 link setup.
