03-08-2011, 10:30 AM
I use Kadee #4's but be warned that Kadee is discontinuing the #4 couplers. The #4 has a narrow shank with a very small hole in it. Right behind the narrow shank it opens up into a rectangle with a tang on one side. The rectangle is designed to hold a coil spring as a centering spring. I cut off everything behind the narrow shank, and drill a hole the same size as the small one in the narrow shank into the draft gear box. I then mount the coupler into the box with a wire. The coupler will not be self centering, but I have not found that to be a problem. I just use a small screw driver or wood skewer to position the coupler to line up with any car that I'm trying to couple to.