I have been successful with this technique: first, I cut the Yakima rails in half because I didn't think I would need that much travel. I epoxied the T-nuts between two pieces of 4mm (be careful to keep the threads clean). The 4mm strips are 1/2 inch longer and 1" wider (1/2 inch above and below)than the rail. I then drilled out the original hole, drilled a new hole in the proper location to accept the s/s hex-head bolt, and epoxied the rail to the 4mm strips. I then epoxied the assemby to the hull with the far end against the bulkhead (requires planning ahead). Advantage= lighter weight and more gluing surface area than blocks. Note: you may have to install the footpegs prior to gluing the rail because the bolt head may hit the bottom of the footpegs.