went to my locale machinist, with the NAS6206- 44 bolts ( these supercede the NAS1100 series ) he will be milling and drilling the wing straps . The 6206 shear pins holes will be drilled by cnc and polished for very close tolerance fit . all other strap holes will be drilled to 15/64 and the reamed on assembly to 1/4 or NAS1104 (NAS6204).