Too much wood?

The most important thing is not to cook in the dirty grey smoke. I use 3 or 4 fist size chunks of oak when I cook brisket. I place two down in the lump and two on top. Don't let them be touching. You want them to be spread out. I light the fire right in the center and allow it to reach 275 degrees. It is usually smokin like a locomotive. That is bad smoke. At this point I close the daisy wheel almost all the way and close the bottom door almost all the way. I want to bring the fire back down to 225 degrees but not kill the fire. This takes a few hours sometimes depending on the weather. Now I have a light blue smoke. That is the good smoke. I put the brisket on around 11pm and let it cook all night. When it reaches 165 degrees internal temp I know I am right in the middle of the stall and the brisket is not going to take on any more smoke flavor. This is usually any where from 8 to 10 hours into the cook. At this point I spray it down good with plain water from a spray bottle, double wrap it in the heaviest aluminum foil you can buy, seal it tight and either put it back on the egg or throw it in the kitchen oven at 250 degrees. Place a meat probe in it. Just shove it through the foil into the thickes part of the meat. When the internal temp hits 195-200 degrees check for tenderness. It do this with the meat probe that is already in the brisket. Just wiggle it around and hopefully the meat will offer very little or no resistance. Now  wrap the brisket in some old towels an place in a cooler to rest for a few hours. Plan on supper around 5 pm. Hope this helps.