Sullivan makes a Kevlar pull pull set up might save a few grams on the steel lines. If this is your first time with a pull pull rudder linkage. try and get the rudder servo centered in the fuselage if possible. you can run two control horns one on each side of the rudder or my favorite a long 6-32 bolt thru the rudder. on the goldberg chipmunk i would have no problem using 2-56 on the pull pull again it will save a few grams over the 4-40. Any doubts about the strength of 2-56 i have been running them on my 140 equipped pattern planes for a few years now and have been completly happy.

Dennis