I am guessing, going by how those are priced, that DLC coating is extra thin and mostly is good for breaking the cam in properly. Nothing like a DLC coated lifters used in the racing world. Normally DLC coatings are on tool steel lifters on billet cam cores, not cast cam cores, and the coating is pretty expensive. Moly wear additives in most street oils supposedly eats away at DLC coating also, but if the DLC lasts long enough to help break the cam in, taking less metal off during the break in period, I would expect that to be very helpful. Plus, as I understand it the finish on the lifter surface has to be extra fine too apply the coating properly, which should provide a more accurate crown on the lifters.
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