There is little that is inter-changeable between the TF and H9 Mustangs. Retraction speed for full scale Mustangs is about 3 seconds for the wheels to hit the wells, a little longer for the doors to close. I used battery voltages from 4.8 to 10 volts to operate the Robart electrics, the actual cycle speed is between 9.5 to 10 seconds, air is much faster and you don't have a hung gear draining the receiver battery. I use 8-32 machine screw nuts to retain the air lines on the nipples. Tie the air lines down and insulate them with spiral split fuel line to keep the lines from rubbing hard parts inside the plane. For long runs I use spark plug cable insulation from auto parts stores. Tie wrap everything down and you won't have leaks. H9 recommends using servos to drive the gear doors, if you do that provide separate battery power. Prop blast will force the doors to open partially in flight, a servo under this much strain pulls 5 amps, it will fail quickly. Driving the gear doors from the door's trailing edge like the instructions say is asking them to blow them off in flight. I use Robart air cylinders to drive mine at the door's leading edge, just like full scale Mustangs do.