I am not an expert, but I modified a cheap Bachman 030 by taking off the cowcatcher, carving the plastic with a razor blade, inserting the Kadee coupler, and reglueing the unit to the correct height; 1/32" above the tracks (bottom of the hose). To glue it, I used the medium viscosity clear super Jet, a tweezers, and laid cardboard directly on the track, put the train on the track. and balanced the coupler on top of the cardboard. I now have a working nuckle coupler in front of my locomotive!