Free machining! Where do you live and can i buy you a beer.
Cam seems fine. Those are pretty heavy springs i wouldnt want to cut the head too much if its weak in that area for those springs.
Might be better to get the correct springs lunati can tell you if they have a set that will work on your heads. They usally will not recommend another compaines product but maybe they know a gm part number that will work.
If they stopped making them they may have been replaced with another part number sometimes compaines will free exchange if the part number is superseeded by another one. Might want to call just to see if they have a better option or found a defect in that design.