Unless you find the exact car that 340 came out of its worth what ANY CORE 340 is. Nothing more.
As far as doing no mods except normal over boring or align hone, any parts inside are moot point. It will still be a 340 core plus some more $$$ to some buyers. I'd pay current Core value and maybe 1/4 the $$$ of the special parts. If you spent $15,000 in the rebuild I'd maybe pay you $5K to $10K depending on parts and who put it together.
Edit. I'd rather buy the core and spend $15K in my own pick of parts and WHO Machines and puts it together.
