Edelbrock valve spring replacements

It's the same cam. See specs here - P4120655 should be identical to yours: http://www.summitracing.com/int/parts/dcc-4120655/overview/

The reason for the discrepancy is the magazine used 1.6 rockers - not 1.5 - so the quoted lift is higher and also duration @.050" is slighter longer with the bigger rockers. You can also alter duration @.050" using more or less lash on solid cams.