Change in plans... Anybody used a "retro-fit" roller cam in a Magnum?

I doubt the valves hit the pistons on a 360 magnum at .534" lift, even without knowing the rest of the cam specs and whether it was installed advanced, retarded, or straight to suggested spec. Every one I checked so far had plenty of extra valve to piston clearance in that lift range, especially on the exhaust side, when using stock pistons, heads, and valves. They all ran out of retainer to guide clearance well before piston to valve clearance was too close. Probably just needed a valve job, or at least a good lapping, and now the sealing issues are showing up. But always double check these clearances on each build, just to be safe.