For a 440 engine build, need advice on blocks and their current values

[70Challenger440]

I am looking to build a mild 440. The first step is finding a suitable block and what to pay. I can be flexible about what I start with. What years should I stay away from? I assume 65 to 72 are the preferred years? What should I look to be paying for a non-HP vs HP block and how does the price vary by year?


Also I am confused about conflicting info on external VS internal balance by year. Is this correct?
65 to 69 (internal balance all)
70 to 72 (HP external balance) (non-HP internal balance)


Anything else I should know? Any recommendations of where to source a block? I would even consider a complete rebuilt turnkey crate motor to keep things simple and am willing to hear recommendations of places that offer that too.

[Bullitt-]

   Have you read this? https://www.440source.com/blockinfo.htm

      Seems to me there are benefits in the later years.....