The 440 small block would be the way to go but the track record of Mopars crate engine quality and the prices they charge are what is turning me off to this idea. If they charge a resonable price this would be the way to go. I'm not ruling one of these out but, I'm not sure if it willbe cost effective compared to what it would cost to build my own big block 440.
Plum6Pak, I do see your point on keeping the 340, I have gone back and forth on keeping the 340 or going 440 for exactly the reason you state. But from what I have seen on the resale market a nicely done orginal 340 car done up as a 440 car seems to fetch more then a 340 car with another 340 in it (assuming that the 340 is not the orginal). So this is why I am leaning on going the 440 route. Also the 340 I have is not a date correct 340, if it was, then I would stick with the 340.