340+ for the STREET

La 318/360 specs haven't changed much.
Even magnum short block isn't very different then there roller cammed LA engine. So you'd have to assume most of the magnum hp gain is thru heads.

Look at the 380 hp magnum create engine.
They dyno over 400 hp with just cam, headers and 4bbl. Even crazy built engines have a hard time hitting 2 hp per cfm but magnum don't. So at least the magnum seems to have an advantage in stock form.

From what I hear ported is where LA shines.