The nice thing about a big block engine is the fact you don't need to go radical on the cam profile to make plenty of power- - - - -there's enough torque available that the RPM can be kept down to a reasonable speed and you don't need a radical cam grind.
I like the Comp Cams High Energy or Magnum series, either the 268H High Energy, or the 280H Magnum models. Here's a spec sheet out of the current Comp catalog:
http://www.compcams.com/catalog/COMP2010/jpg/COMP_Catalog_2010_202.jpgThe 268 works well with stock compression and rear end gears, while the 280 needs a compression bump (9:1) and either a high-stall torque converter or low rear end gears with a standard transmission. If you're running a 3/4 ton or 1-ton rear axle, you've probably got low enough gears already to use either cam. The 280 will definitely give you an idle lick, but you'll lose a little low-end torque in the process.
Jerry