I'm considering purchasing a GSP Hellcat. The big hold up is that I want to put in retracts. The airplane is advertised to come out around 10 - 10 1/2 lbs. I read somewhere that putting in a set of Robarts 615s' takes alot of modifications; lots more than the GSP Corsair. Being around 10 lbs I don't think the Hobbico 90 degrees rotating retracts will work. Any input on this airplane would be gladly appreciated.