Well, here are my
opinions...
340 Six Pak - very good all-around engine, good performance, stock appearance, lighter for better handling of the car
440 Six Pack - excellent engine, better choice for straight line performance, some "Wow" factor added to car
426 Hemi - EXCELLENT engine, great peformance, big "WOW" factor, but some tuning experience needed to make it run to its potential (if you go with a Hemi crate motor, I would recommend the 472 CID variant from Mopar Performance)
392 "New" Hemi - so far it sounds like a great motor for performance, not sure of the pricing yet or what other expenses may be required to adapt it to the older Mopars (sounds like DCX is aiming it at this market, so may not be a big issue)
Since it sounds like you want a "big" motor (and I assume the "Wow" factor), I would recommend the 472 Hemi... If you want a great
all-around performer with a "Wow" factor included, the new 510 HP 392 Hemi being released soon by M-P might be the best way to go... On the other hand if you have significant budget constraints, the 440 Six Pack route would be a lot easier on your wallet...
Just my opinions... a bit biased to Hemis...
XS