588 big block mopar

To me the answer is more HP in a streetable package. Build a 600hp 340 and then a 600hp 440. Let me know which costs less and which is more street friendly.

If you are pushing the limits, especially N/A, more HP is easier with more cubic inches. Look at the size engine you see on street outlaws or in the unlimited class at drag week. You also need to take into consideration the strength of an aftermarket block vs. a stock block at higher levels of HP.