In one TZ ep about a killer he mentions how a sheriff in DODGE CITY tried to beat right and wrong into him with a wet rope. This is clearly an unofficial reference to Gunsmoke as they could have had the killer says it was, say, Denver.
Chester himself Dennis Weaver guested in TZ.
There was at the end of TZ ep many times a shot of a drawing of Marshall Dillon and you hear James Arness's voice saying I think to watch him a certain night of the week in Dodge.
Later superstar Burt Reynolds was Quint on Gunsmoke and he also guest starred on TZ.
Loads and loads of TZ actors guest starred on Gunsmoke. Like Pat Hingle and Dabbs Greer and John Dehner just to name few.