I didn't know this but on that interview with Tom on the 4th season",

he says that he actully read for the part of Bo before he got to play Luke".

So what I'm wondering is why did he get the part of Luke and not Bo ?

even though I know that they were having trouble finding someone to play Luke I just was wondering how did it end up going to John instead.

Because they wanted someone younger then 24 to play Bo. They were wanting someone that was in there 20. Tom was just too old for the role of Bo but prefect for the role Luke Duke.

When you audition an actor, you hardly ever just have them read one thing. You want to see the range of what he can do. Odds are they just had him red for Bo to see how he handled Bo's material, as well as Luke's.

According to most people's recollections, John was essentially already getting the part of Bo, so long as casting could find someone to play off of him. They probably never had Tom in mind for the part of Bo, but they did want to see how he'd handle being the more rash one.

Perhaps trying to find the balance that would work between the cousins - who would be more likely to say what and how, etc.

Also maybe to see how Tom looked as Bo as well. Just because he read in doesn't mean that he was ever really considered for the role of Bo. I heard on some commentary that as soon as they saw Tom they wanted him for Luke....I can see why, with that rugged, kind of responsible older sibling thing going on whereas Bo has a more cheeky grin.

Excellent casting I have to say, if only they could have gotten that in the poor 2005 movie.

I just can't see Tom as Bo. It just wouldn't have worked. But that's my 2 cents.

Tom was 26 when he got the part of Luke Duke. and I couldn't picture him as Bo Duke eather.Tom was perfect for the part of Luke Duke.

People often underestimate (great topic by the way) how difficult it is to actually be cast in a part. Hollywood is a very competitive business and sometimes even big name actors struggle to find parts. Factor in that all the younger cast members of the Dukes were basically unknown (James Best, Sorrell Booke and Denver Pyle all had some success before the Dukes) and many unknown actors go to tons of auiditions before they are offered a part. Sometimes they will read for multiple parts. You just never know with television, quite often people initially have another actor or actress in mind for a part or their idea for a character changes. I remember seeing recently that Henry Winkler (The Fonz) was only intended to be a minor character in Happy Days and he ended up being the star. You just never know.