Longer duration, more lift? I was wondering about the heads, too. There's a bunch of things they could have done - cam, intake, exhaust, throttle body, it just boggles the mind. Well, it boggles mine, anyway [:-]

dave

 

geeze dave if you are like me it doesnt take much !!! lol

 

Notice the higher compression ratio (now 10.5 from old 9.6?)
and the variable valve timing similar to the Viper V10
which complement each other
and provide the 'overall' 4% improved fuel economy
....probably more when in MDS now

 

dave

 

It is a new overhead cam design with variable cam timing, instead of the current overhead valve design.

From allpar.com:

2009 Hemi: 380 hp / 404 lb-ft

Variable cam timing, a state of the art method to raise efficiency, was introduced for the 2009 model year. Other changes include a higher compression ratio; higher-flowing heads, intake, and exhaust; and an active intake manifold that switches from long runners to short runners, to optimize the engine for either better high-end horsepower or better low-end torque. Other upgrades to raise reliability and durability are crankshaft structural upgrades, a dual-mass crankshaft damper, floating pin piston design, valve spring design, and oil pump capacity increase.

The results of all this work are a 10% boost in power to 380 hp (283 kW) and 404 lb-ft of torque (548 Nm), up from 345 hp and 375 lb-ft. At the same time, gas mileage increased by nearly 5% in the Ram, partly due to aerodynamic work, but also due to a more active MDS system and the variable cam timing’s ability to close the intake valve later, pushing work to the crank instead of rejecting it as heat.

 

compare what was done to the 5.7 V8
to what Audi is doing to their gasoline engine line:

http://www.carpages.co.uk/audi/audi-...s-09-02-08.asp