Over the weekend I spent a lot of time on making sure the Sitka Spruce Stab Spar 84 inch lengths were exactly 1/2 " x" 1 3/4 ". This is because the square holes in the Stab ribs are exactly 2 1/16" square. I also used a Maple block vs a Birch block because I could not find a 1" thick birch board and maple is an acceptable substitute. Also in the picture are two Balsa wood blocks to be used in the filler space where the Stab trim rod passes through the Stabilator.