To me, it would boil down to who put the Monte front on the car. Was it done by a pro shop or a really sharp rodder who knew what he was doing? If it was done by some yayhoo in the back yard, then I'd opt to change it out so I would absolutely know that it was done right. If it were mine, first I'd get the car flat and level on a level surface and I'd plumb bob it and see that the measurements are within 1/16" of each other, each side front to rear and diagonally. I'd make sure the lower control arm mounts are the same distance to the ground side to side. If all that was good, then I'd shop for narrower control arms. That's just my opinion.