I'm using Robart 3" diamond thread scale wheels. No problem running the air line. I had to grind a notch on the bottom of the rear gear box cross webbing for the air line to clear:



The air lines also need to move freely as the gear retracts and extends. I used an electric hot knife to cut away the factory installed plastic bellcrank so the air lines don't bind on it:



It's too bad I couldn't completely remove the bellcrank because I believe there is a nut at the top of the mounting plate holding the bellcrank mounting screw in place. Turning the mounting crew would only make it go round and round without loosening it. To get access to the nut, one would need to cut a hole on the top of the wing, and I didn't want to do that.