So after talking to people at Lang, and researching, I found that most high end smokers have inlet vents in the FB doors opposite the smoke stack. What makes a Jambo pit so nice, is that exact quality. The smoke stack on a jambo is right in the middle of the chamber, and the firebox is so huge, the vents seem like they are within crosshair of each other. Having said that, the lang is designed differently, and I have been given really good advice for keeping close temperatures across the chamber.
First is to build a good fire with nothing but a bed of coals and embers. I have been told it is nicer to have a basket made to keep the embers and coals closer together. And also to add smaller splits of wood and to keep the fire as far away as possible form the opening into the smoking chamber.
Second, is to have the nose pitch of the grill pointing a bit above level. But only enough to still have the griddle baffle plate drain test water down the drain. Reason why the baffle plate is designed to have a considerable downward slope when you have all level is to allow a slope even when the cooker is pitched up a bit. This allows, according to Ben Lang and other highly experience Lang'ers, to have better heat distribution across the grates. With maybe only a 5-10 degree difference from bottom to top level grates. The way I had it setup was with the cooker having a downward pitch. I will do further testing this weekend and will come back with results. Sometimes it is good to have zones in a chamber.
And finally to keep everything even closer is to do cheap mod that only involves bringing the stack down a bit with 7-10 dollars worth of homedepot materials and is none permanent. This pic was taken from the lang forum, check it out, talk about the mod.
http://lang.myfreeforum.org/Mods_To_Lang_36_about421.html
I would wait to try it out first with these tips, before moding the firebox like that.