After getting the exact measurements of the distance from the back of the front spar to the middle of the rear mounting hole + 3/8" we filled down the rear T-bone to match this distance with the distance from the T-bone to the rear mount on the fuselage. This took quite a bit of filing. After that was achieved, we then took the exact measurement inside the front spar and cut the front of the T-bone so the distance between the t-bone "arms" was exactly the same as the distance inside the front spar at the bolt holes. LOTS of filing!