A simple test anyone can do is this. Put the cam in with no lube on the lobes, just oil the bearing journals. Put the lifters in with wd40 on the sides, mark a spot on the lifter with a sharpie. Rotate the engine over a few rounds, and verify the lifter is rotating. If it doesn't, it WILL fail. Sometimes it's a burr in the lifter bore, but most often it is incorrect machining of the lifter faces. Doesn't matter WHO you bought them from.