With the mods listed in my sig I can easily blow a ton of black smoke, if I floor it, it will smoke black from 0-35 or 40mph, than it turns a greyish color. Lose the K&N filter!!!
The secret is to overfuel the engine, so get a chip with a tune that has really heavy fueling. you'll get even more smoke if you have a clogged air filter
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Of course, smoke isnt everything, it usually does signify that your truck is putting out some power, but it doesnt need to smoke to put out power.