Is there a way to adjust hot spots in a horizontal smoker setup? I have a combo gas/charcoal grill: 



I have an offset firebox that attaches to the right side that I use to convert the charcoal grill to an offset horizontal smoker.

However, when using the offset to smoke, I have noticed that there is about a 10 degree differential between the right side of the grill, and the center.  This is problematic with larger cuts of meat (boston butt, rib racks, etc.), and even with large trays (such as smoked almonds), as the side on the right cooks significantly faster.

Aside from rotating the food regularly, is there anything I can do to reduce the temperature differential created by the hot spot?
Basically, what you need to do is create a baffle that distributes the smoke further into the main chamber. 

Checkout the mod #3 in this PDF for a CharGriller Smokin' Pro modification. 

http://www.deejayssmokepit.net/Downloads_files/CharGrilleMods.pdf

You can do this same thing with tin foil if you're on the low budget plan.