Black Dust ?

[soup]

here we go again ,engine 350 crate 290 hp chevy every thing is new, previous problems are on other threads, rough idle,just put new msd wires,rotor and cap on ,noticed old rotor had black carbon dust underneath,two days of new rotor and black dust under it, runs like it is crossfireing, no other carbon tracks on cap or rotor,is black dust normal?
attached picture