The Elgin and Comp grinds look to be pretty similar from the specs given, with the Comp probably having a slight edge due to a slightly more aggressive lobe.
The bigger exhaust lobe on the Herbert cam will help on an engine with a comparatively weak exhaust. That's from the valve to exhaust tip. Mopar small blocks tend to have quite a good exhaust port so I'd say if you are planning on running headers and decent-flowing mufflers then it might not provide any benefit.