Am looking for best backpack blower have been searching forums on here and it seems 570/7500 or 580/8500 are the best. From what i understand the 570/7500 scours the ground better where the 580/8500 is more power with less control. I looked at them today and noticed the 570/7500 tube end is smaller at the end making the air more controlled and the 580/8500 is flared out at the end. My question is could you put the tube end off off 570/7500 on the 580/8500 and have the best of both worlds with more air volume plus more blowing control in tight areas. Sorry for the long post.