Bachmann HO coupler box replacement

[rako]

My grandson and I are new to model trains and could use some advice on replacing a broken coupler box for a bachmann Sant Fe GP-40(#3507)locomotive.
Do we need an exact replacement and where do we go to get one?I have browsed suppliers and am not sure what fits.
Dwight R

[WoundedBear]

This Kadee link may help.

http://www.kadee.com/conv/pdf/b10.pdf

Sid