Today’s cams have more aggressive lobes. That’s why increasing the oil supply to these lobes is critical. Howards Cams uses a precision “E.D.M.” laser to burn a .021 in. hole in the center of the face of their direct lube extreme-duty mechanical lifters. This allows for a constant oil supply to the cam lobe, resulting in higher valve spring pressures, more aggressive profiles, and reduced lobe wear. This is a heavy duty solid lifter! This is our top choice for all solid flat tappet camshafts.