[Jay S]

For stock cams like a 066 or 068 I do not think the lobe width will make any difference in longevity. On stock type cams I think the narrower lobe is easier to break in, and the lifter machining doesn’t have to be quite as perfect. Some of the original factory Pontiac stock cams were ground on the narrower lobes, they were not all wide lobes. On bigger cams where the profile is using more of the lifter face the lobe width is a lot more important. A big profile on a narrow lobe there ends up with less footprint where the lifter has the highest acceleration. That is why most mechanical cams use the wider lobes and the EPC cores are EP-2 instead of the standard cores. What I have seen on the narrower lobes and bigger profiles is the lifter digs into the base circle the closing side of the base circle, and the taper gets removed quicker on the opening ramp.

Comp cams and generally uses narrower cam cores from EPC. Crower uses the narrow lobes also. The letter EP-1 or EP should be cast into on the core somewhere between the lobes on EPC cores. Melling always uses CMC cores and has a little wider lobes with the letters CWC cast into the core. Both EPC and CMC cores are cast at CWC though.