340ci vs 360ci engine
The Chargers are cool and now it's totally outside of this discussion but I'd go with a stroker 400 R block if I were building a B-body. There was actually a 400 block and a 500" stroker kit from 440source on our Craigslist last week for $500. It's gone now! That makes awesome power but revs better then the 440. It seems performance heads and stroker kits are a little less for the big blocks then the small blocks, and a B-body has all the room in the world under the hood. Also those years of Chargers you are looking at very likely might come with a 400 under the hood.
Also do you know about moparts.com they have a very good and organized classified section.