I'm building up a trek Madone 5.9 frame with ultegra group. Unfortunately the front brake bolt and 25mm pivot nut are too short to meet in the fork. After a couple measurements, it doesn't look like a 30mm or 32mm nut is enough, and that seems to be the longest readily available. Anybody know where I can get a 35/38/40mm long nut, or perhaps a longer bolt for the brake?

Brakes are ultegra br-6700.