Damn good info

Hughes has a spring,retainer,locks package that is drop in,good to 540 lift for $200.00

We also have one, not a conical though but fits the OEM rockers, allows .550 lift, 125lbs. installed, and 260lbs. open at .550 lift. It runs 230.00 for the springs and retainers, no machine work and you can use the oem locks.
Springs not a big deal...the magnum is a great platform!