If anyone is interested, I finally got the retracts installed. For the nose-steering there was room for a 10 oz. tank. The only problem is the steering cables. In the fuse I mounted the air tank just behind the #3 header. The rudder and elevator servos are side by side just ahead of #3 header and the wing bolts. The throttle servo is mounted just ahead and on the side for a straight connection to the engine throttle arm. The manufold for the retracts and miniture servo is then mounted on a plate on the opposite side. this leaves room for the 2.4 gig received and battery. The aleron servos are wing mouonted so there is no center servo in the wing, just connecting wires and air tubes. Air fill valve mounted just under the manufold and servo. I haven't checked ballance yet, but should be ok. Its all a tight fit, but works.