Installed the F-1294 Tail Cone Fairing Assembly (again) to check the clearance with the H-Stabilator. Drilled #40 holes into the TC Fairing and Tail Cone and then clecoed. The TC Fairing Assembly was being touched by the H-Stabilator skin during movement, especially on the right side. Removed the assembly and trimmed the skin of the H-Stab (top and bottom, and left and right). This took a lot of time. Final-drilled the #40 holes to #27 and then deburred them. Reinstalled the assembly and checked the required clearance. It is better but some trimming of the H-Stab skins and the TC Fairing assembly is still needed. Attached the nutplates to the #27 holes with screws. I could not drill the rivet attach holes even with a small right angle extension because of the limited space. I'll need to get a long #40 drill bit to continue with this step.