moper said they come with the HP spring. I've never seen one that did OTHER than the Melling HV pumps MP used to sell marketed as high pressure and high volume. MP would take the Melling pumps, disassemble and clearance them then install the high pressure spring package and rebox them as MP HV/HP units. Used many of them through the years. If the regular Melling HV pumps had the high pressure springs in them, it's news to me. Evidently Mopar Performance didn't think they did.
