A year or so ago, I bought the DVD Gunsmoke: The Directors Collection.
Among the bonus features are four episodes of the radio version. You probably knew William Conrad was Matt Dillon. But did you know Parley
Baer and Howard McNear (both later regulars on TV's Andy Griffith Show) were Chester Goode and Doc Adams, respectively?

Yes I read/heard the William Conrad was Matt and Howard Mcnear was Doc. When ever I this of Howard I think of Floyd the barber on the Andy Griffith Show. I wish we had some radio shows. It would be nice to hear while driving.

...was on radio for nine years (1952-'61), and most of the scripts were adapted for TV during its original half-hour edition (1955-'61). CBS didn't want William Conrad and the radio cast because they felt they weren't "telegenic" enough [you probably know the network initially wanted John Wayne as 'Marshal Dillon', but he didn't want to star in a TV series, instead suggesting a young actor under personal contract to him- James Arness].

:tv:

and John Wayne introduced the first TV episode.

the radio version's GREAT. I have a lot of episodes of it on cassete (now I need a cassete player; as I haven't played them in YEARS) that I recorded off the radio when a local station used to play old radio shows on weeknights back in the 80s. (something wich a lot of stations did back then but sadly they don't any more:( :( ) and I sent away for them from a mail order company I used to have a catalog for.

I heard that sattelite radio plays the old radio shows; and I know that some web sites also play them.