Fabrizio,

I would mark the centerline of the trailing edge of both stab halves. Then install the stab halves in a short tube so that the stab roots join together. I visually sight the TE centerlines with a straingt edge to check the dihedral. Another way is to install a short tube in the stab halves and mount them in the stab bottom side cores. You can then measure the height of the stab to the centerline marks. This should tell you how much dihedral you have. If the difference is less than 1.0smm than I would use the stabs.

I usually check my dihedrals (visually) on my stabs before I install the stab tube sockets. By the way, I just now checked for you one of my stabs from an old Eclipses. It has no dihedral in it.

Hope this helps.

Steve