Negative Height Valve Spring Retainers

When I switched my buddy’s heads over to LS spring package I had to cut them down for .500 seals. them I had to use negative retainers and keepers to get enough spring pressure for a .660 lift cam. .060 coil bind do we cut it close. PAC was satisfied with how they were set up.
In hindsight I should have just done the bronze guides first thing. These heads were not supposed to get this complicated, lol.