Dave Platt has a 80" Zero at 15 pounds with a battery box under the upright motor. Its a proven design with a OS 108 for power. He states it flys well at 22 pounds using a bigger motor. Mine flys much faster than scale with the os 108. This is at sea level, if you are in the mountains of course more motor is needed. If you use common sense to secure the battery you don't have to add lead at all. I hate dead weight more than anything. A OS 160 is way over powered for this plane. Of course if you want a 3D Zero to circle the Moon please feel free to do it.

Carl