MWB-- I just bought a mounting plate from Titan and a pair of used forks. I had plans to make a fork lift just like yours, but the face of the plate is about one inch too deep. I can't weld a 1/2" bar to project above the plate and a 1/2" bar to project below the plate for the 16" depth of the forks. I had planned to use 1/2" X 4" bar stock where you have spec'd 1/2" x 2 1/2" , and run a continuous weld along the top and bottom. In order to accommodate the 1/2" lip at the back of the forks' mounting lips (too many lips here) I will need to space these bars 1/2"- 9/16" out from the mounting plate. Doubling the thickness of the bars seems like overkill, and using bolts just assures that they will interfere with the sliding forks or the QA function. Any suggestions?