383. No replacement for displacement. Fords 5.0 is a good motor, but suffers from a two bolt main, and four bolt head pattern, both of which are detriments to potential. I do not know enough about the new Hemi.
The general rule about Dodges is you need three cars to last long enough to exploit one motor. Sure the Hemi can make power, but the cars around them don't make buying one worthwhile. I am guessing though, the Hemi has a strong block architecture, but has not been exploited by the aftermarket.
This is a bit unfair, as the Hemi is a next gen motor and the other two are at least one generation behind. If you compare the LS with Ford Modular and the Hemi, you end up with a closer group. Having experience with only the LS and Modular, I would use the modular....to anchor my boat. The Hemi might have potential, but until they wrap a car around it that is worth the effort, they can keep it.
LS...no contest