I have a 68 Charger that is currently a bare shell. As I am working on it I need to be deciding what to power it with. I would like some form of a big block at this time. It will be a 727 car ( manual valve body) and a Dana 60 ( don't know ratio yet)

I am seeking opinions on what type of big block I can get away with on a street driven car. I do not have ET goals in mind, and I do not mind a rough idle and low vacuum. My first thought was a 400 based 470. The car will have to run on Pump 93.

So, with no parts to start with, what would be a good combination and what compression ratio can I get away with? If I have not provided enough information please let me know. Thank you.