Metal in oil
Your metal on the drain plug is more than likely coming from the cam lobes and lifter faces, working against each other.
Not running zinc and higher lift cam and higher pressure double valve springs are putting the cam wear and lifters to the test.
Knowing you have an issue, I would swap out the high pressure valve springs to the new lighter pressure single coil valve springs. As long as you are not winding it up over 5,000 rpm on a regular basis you will be fine.
Reduce some pressure on the valve train and use the zinc additive until your oil cleans up and no metal is showing up on the magnetic drain plug.
☆☆☆☆☆
Your metal on the drain plug is more than likely coming from the cam lobes and lifter faces, working against each other.
Not running zinc and higher lift cam and higher pressure double valve springs are putting the cam wear and lifters to the test.
Knowing you have an issue, I would swap out the high pressure valve springs to the new lighter pressure single coil valve springs. As long as you are not winding it up over 5,000 rpm on a regular basis you will be fine.
Reduce some pressure on the valve train and use the zinc additive until your oil cleans up and no metal is showing up on the magnetic drain plug.
☆☆☆☆☆