The length of the Dubro plastic arm doesn't matter. I think it's about 2.5"

I'll make my aluminum plate about 3.25" long and drill my holes exactly 3" on center to match the rudder horns.

I'll just run a couple 2/56 bolts through the aluminum plate and down through the plastic DuBro arm. Then put nylon lock nuts on the bottom of the assembly.

Thanks to Gene from Troy Built Models. He's the one who gave me this idea. [sm=thumbup.gif]