Pics-3 of 3--. Next, I moved back to the GPS antenna bracket. I received some stuff from ACS, including adel clamps. I installed the clamps around a cross support on the motor mount and clamped together with #10 screws. Then I used safety wire to keep the clamps together and removed the screws. With the antenna shelf in place, I used a short bit thru the clamps to mark the bottom of the antenna shelf. Removed and drilled holes to 3/16”—also trimmed off about an inch from the front of the mount. The mount is now very stable—next up is to drill for the antennas and add nutplates to rear of the mount.