Getting ready to drill spar holes. The angle of the fins ar 118 and 120 degree. The spar provided by Eagle R7D however is more like 120/120 degrees, which means it will not be completely parallel to the leading edge of the fin. Next I drilled the four doubles on the lower fin and Installed Clecos. I used a straight pice of wood to determine wher the spar is located inside the fins by aligning it with the spar. The piece of wood sticks out on either side of the fin and lets me determine where the holes need to be drilled. I removed he lower 4 rivets on the lower fin. This makes it much easier to push the spar through the lower fin without scratching it up to much and these rivets are easily replaced later.