1000 hp 340?

The Gen3 Hemi factory blocks can handle more torque and horsepower before failing than production small blocks, and the heads flow a lot of air.
Plenty of guys making them fit A bodies, so no real reason not to run one, except I mostly have street junk and it's been way cheaper to build Magnum engines.
The 5.7 versions of the Hemi have really come down in price though, and are easier to find as cores in junk yards now.

From what I have been reading on the 5.7 the head seems to be the week part when you start throwing boost at it. Seems like most guys are switching heads.