There is nothing wrong with cutting up a dually because they are all over the place but if you cut up a TRUE Grand National you should be shot! Just get another clapped out Regal and slice it up to look like a GN. I have a 87 GN with 26,000 orig miles and I won't put a rollcage in it because you can never go back unless you want to patch some big holes and then you take away from the true value of the GN. Heres my 11 sec. street car on 18's!