Todd,Im running both a 27 and a 26 Trophy on my Puma/250 Pro XS, depending upon load and air temps, but I dont run a blowout ring on either one.With the 27, I have all four holes plugged with solid plugs, and on the 26, I have 3 solid and one small open plug. I have never been able to run the blowout ring and make it work right. If you need or want a ring, just let me know, I have several in my toolbox, and Ill just mail one to you, but I dont think you need it.And, with the grass levels we have on Pickwick, there has been no problem with grass behind any of my props.Mike Whitten