black soot on rear bumper
 

I get this black power out of my tailpipes. It really shows up bad on my white car and look awfull. The car seems to be running alright and I don't know what to do? Any ideas on what to look for?

I should mention that I have a carburated 306 with, a comp cams 280 cam, no cats and dynomax race magnums. The rest of the mods are in my sig.

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4 cyl converted to 302
comp cams cam, ported GT 40 heads, Edelbrock intake, holley carb
Turbo coupe rear with 373's
4 inch cowl hood
finally done after what seemed like forever!!!!!

Need to extend your tail pipes out a bit more. It happens even to hard run EFI cars. That's one of the ways I check out a used 5.0 black tail pipes and a bit of smut on the LX cars tends to indicate one that has been riden hard and put up wet. Unless the carb hasen't bee ndialed in I think the the condition is still kinda normal