3G Hemi vs LSx vs Ford Mod Motor - which is the 'best'? And which to put in mopar?

Yes it does make it a superior swap engine.

It only makes it superior in a cost sense. I know cost is a huge factor, but from a purely technical stand point, it kind of like comparing the color of the block.

As for the dyno numbers:
http://www.truckinweb.com/tech/1208tr_5_3l_bow_tie_builds_mild_to_wild/

Just adjust for a 20% substraction. The base puts that around 290hp.(yes it has headers, but so would most any swapped LS or hemi.

Funny, I saw that same article today. It also has an aftermarket TB, Fast management and no accessories. Not really a very good example.

I did find a guy that was complaining that his 5.3 only made 230-240 rwhp on a dyno, though. That seems more like a real world example. And the example I was thinking of was a factory rating which meant no headers.

And I think your 500 hp rating is a little low for the factory hemi shortblock.