whats this "340 car" worth?

Hi all

I came across a 73 Duster descroibed as follows:

340 duster,340 motor,727 trans with stall converter,holly intake, carter carb,hooker super comp headers,lugoni cam and lifters, motor is fresh, posi rear end, with 373 gears, fresh paint, inter needs work, but not too much, sounds good and runs and drives great. 5000 obo

The car also has front disks.

After speaking with the owner, he doesn't know if it was a 340 car or not originally...the interior needs replaced...no door panels, front seats are "ok" in his words but dont look correct....headliner is shot he says. Dash is nice he says. He just painted the car not long ago and has owned the car for only 6 months. He said he bought the car from a buddy to help him out of a jam and he is a chevy man and knows nothing about Mopars and just neds to sell it.

He told me he and a buddy redid the engine...the tranny had new seals put in it (front and rear).....

Here is a link to some pictures.

http://s349.photobucket.com/albums/q391/shadango_bucket/340 orange duster/?albumview=slideshow

What do you guys think?

When I go look at this I would be looking to be sure its a 340....any tell tale signs aside from looking at the engine ID pad? The engine is painted so that me be hard to see.....

Thanks for your help and advice!