Which bachmann couplers should I use to replace missing ones on your bachmann amtrak passenger cars?
This would be my choice if I were changing those, I have the same car set
http://www.kadee.com/conv/hocc14.htm
Scroll down to rolling stock and you'll see Amtrak, there is a tiny bit of modification but easy and you won't be disappointed, just make sure you use a coupler gauge.
You could also go here and use the Bachmann replacement with no altering but you really need to check the coupler height.
http://www.thefavoritespot.com/p-3007-bachmann-ho-scale-train-couplers-e-z-mate-mark-ii-knuckle-center-shank-long-78024.aspx