Putting a new cam in my 360

The cam assembly lube is there to protect the lobes and lifters and what not WHILE the engine first fires/runs until there is good oil pressure and coverage there. Oil doesn't instantly get on the cam. It takes a while for it to make its way onto everything and coat it sufficiently. That's where assembly lube comes in.

What cam break in procedure did you use?

Coated the cam, lifters, etc in the oil additive, made sure there was plenty of oil in the valley, etc. and then primed the system to get things pumping before firing, then running at 2k rpm for about 20 minutes.

It sounds like I was lax on the break-in procedure.