Hi all, have been made an attractive offer for a set of GT blades to retrofit to our existing Hartzell hub, some improvements in weight are obvious, C of G sorted with a lighter tail wheel but would really like to hear from anyone who has done this mod and what the real world changes are. The company claims that a lot of sets have been sent to the USA so someone out there has done this and we would love to hear from them. It is not an easy exercise here in New Zealand, the prop has to go to a shop, new weight and balance, (which I would have done anyway), the biggie being how much phase one testing our feds are going to want done. Best regards to all Jon Ludgater