Did You ever hear this "tired" 340 run??? Yes, there is a market for that era 340 for sure, and that barracuda would still be a lot of fun w/a stick & a warmed-up 'teener!!
Was that 340 a stocker? And was it out of a 4spd car? If so, You might get a nice chunk of ching for the cam alone. Keep in mind whatever mill You end up with has to
have the crank drilled & finished to size for a pilot bushing, or You'll have to use the Magnum insert bearing in the rear of the crank. Not a biggie, just FYI.