the new hemi has the primary advantage of the old one in the vastly superior air flow afforded by the cross flow valves...and the fact that you can run much larger valves and subsequently larger ports because of this arrangement vs traditional wedge heads...the new hemi heads flow almost as good a a rat motor, despite the small bore...

...plus, the hemi's valves open "on-center" meaning they center themselves in the bore and away from the head for virtually zero shrouding.

I don't know...when a run of the mill hemi displacing some 345ci pushes my friend's 5000+lb truck to high 14's, I don't really think that it's lacking in any department...

...and then, there is the srt-8's engine