I, for one, would rather put a 528 Hemi crate engine into that 'Cuda. It makes only 10 less HP and the same amount of torque with 43 less cubic inches. Plus, it's a Hemi. You just don't put Chevy motors where Hemis should go.
It might also be fun to take the new 57L "hemi" and stick it in a late-60s Mopar. 345 net HP is plenty of power for almost anything you'd use it for, plus it would have 2004 conveniences like fuel injection, and with it not having to pump the carb twice before cranking the motor. A lot of Ford folks do the same kind of thing with taking a 4.6L 300hp engine out of a newer Mustang and shoving it into a '65.