first oil change.... should I be worried?

[maxum_101]

hi all

just wondering if its somewhat normal to have a build up on the magnetic drain plugs, i did my first ouil change on the 351 w stroker motor (392) from ford motorsport approx 700 miles on engine, its like a black slimy gunk but it is magnetic cause when i wipe it off on my finger and go near the magnet again it pulls back to the magnet, also the old oil in the sunlight shows a bit of metalic looking residue in it, i keep reading about crank bearings causing that residue in the oil, now here the question ... for a new engine will it give off residue like im trying to explain, in my oil and on my magnetic drain plugs , is that from the break in ? im scared s--tless that there might be some problems with my engine.

any experience on this would be great