I just build this pass winter a 2002 5.3 Lm7 for my truck. its the first motor i built from a bare block. well i went to change oil on it today and when i pulled out the drainplug i noticed that there was some metal on the magnet. not shavings but a very fine almost powder like. the motor has maybe 500 miles on it. is this normal for a new motor just breaking in or do i have a problem i should be worried about?![]()