I agree with Paul. You need to call Darton to find out about this. There were older bows that had cast magnesium risers with the steel cylinders for the limb bolts that were called Mavericks. They are mostly the same as the later Mustangs, with magnesium High Energy wheels. If you have one of those, I can almost guarantee that you will lose draw weight by putting CPS cams on it, and the draw length may be seriously too long. In addition, you may not have a deep enough cutout at the limb fork for the CPS cams to clear the limb. You certainly should be able to put CPS Extreme cams on an older Maverick with CPS Express. Not sure about draw weight changes though. Best to call them and find out.