Kiwi, there could be some variance in that number, due to placement of the mains (straight gear, or the DeLoach gear forward mod) and of the tailwheel. On our DE Stubby, our mains are 1.4" aft of the wing leading edge (when at backbone level attitude, as when doing weight and balance measurements), which is the DeLoach gear forward mod, and our tailwheel axle is at 158.8". The distance between them is 157.4".