Negative Height Valve Spring Retainers
Crane multi-fit retainers combined with standard or offset locks used to give you loads of options provided you didn't use a combo that causes the retainer to hit the "armpit" of the rocker
no idea if they are still made but you could get a mopar sized hole retainer, offset up or down and use appropriately sized locks for your valves that you could also get offset up or down.
no idea if anyone continues to make crane branded stuff