Oil Pressure Dropped...
changing the cam and intake should have no effect on the oil pressure. Something got futzed.
Not saying you did this but ? A long time ago a buddy of mine used a ton of silicone when he built his motor, well, after a couple miles the oil pickup got clogged with cured silicone worms, and dropped his pressure.
Could be a problem with the pressure relief valve in the pump as well.
I'd drop the pan and inspect it.