Hydraulic Roller Lifters

JoJo said
Elgin:
Lift: .454/.454, Duration: 272/272, Duration @ .050": 216/216, Lobe Separation: 110 LC

Comp Cams:
Lift: .454/.454, Duration: 268/268, Duration @ .050": 218/218, Lobe Separation: 110 LC

Herbert:
RPM Range: 1200-5700, Advertised Duration: 270/280, Duration @ .050: 215/225, Lift: .440/.465, Lobe Center: 112c

With the Elgin and Comp cam, would there be a huge difference in those two cams? Also, what is the benefit of the Herbert cam having a longer exhaust duration for a SB Chrysler? Would it help or hurt performance?

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.