a dyno results of a factory stock 426 hemi pull, 490Hp/490 ft lbs.

so that's a base line, and not including the losses through a transmission and gears to tires.

With original dual points, belt driven water pump, and you can image that some performance parts like headers and better ignition would bring more power.

http://www.forbbodiesonly.com/moparforum/threads/stock-hemi-dyno-pull.128297/