I am not familar with conversions of large scale. My experience is primairly with N scale and converting O gauge 3-rail to O scale 2-rail with body mounted couplers.
However: The Kadee "Large Scale Conversion List" at http://www.kadee.com/ lists the 831 coupler for Aristo Craft G gauge and the 1831 for Aristo Craft #1 gauge "rolling stock". Kadee also has a page with conversion instructions. No instructions for Arist Craft "rolling stock" but something there might help.
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
I 'm a beginner, I want to instal kadee coupler on 40' boxcar I learn,few week ago, it's the better mounting for a free rolling freigth car but I don't know the better vay for this. I have buy #820 kadee coulper for try but on the aristocraft there isn't any base for fixing. I'm lost.
sorry if my english is not very well
See you later
Nicolas.
Get the Garden Railways newsletter delivered to your inbox twice a month