How much would you pay for this 340?

What is a core 340 worth ? early vs late? then you have to determine if it is actually a 340 meaning forged crank, block, pistons etc. you know you have 915 Js but are they 2.02s? its a given you'll rebuild it. Id obtain a borescope and look at the pistons and valves etc. make sure the crank is forged etc.