Norfolsouthern...

Try a 13x4 on your Tango, you may like it. It will stay in the optimum RPM range and give a lot of "pull". You lose to end speed but you don't want that type of plane going too fast anyhow. I ran that prop on a 3D profile and it was a nearly perfect match. If ground clearance is an issue just put bigger wheels on the mains.

Like RCKen said, dial it for maximum RPM then back it off 2-3 clicks or until you get a 200-300 RPM drop and it will be fine.