The last time I contacted Mopar tech about the "590" solid lifter cam that had a number stamp on the back they told me that # identified the vendor who made it , not the grind
I called about the cam having .557 net lift at the retainer instead of having .590 like they use to advertised, they ended up telling me that they had switch vendors earlier that year and had dyno tested the new vendors .590 grind and it was still good even though it didn't have .590 net lift in my motor. To be honest about this I had not check the lobe lift on that cam before calling them, I did end up learning later that a lot of the ductile rocker arms made back then didn't always have the true 1.5 ratio built into them
I now check both the lobe lift and the net lift at the retainers with soft checking springs and sometimes again with the race springs to see how much loss of lift I get on that motor