Keep in mind that your hardwoods (oak hickory) are a higer BTU. I run fruitwood for smoking butts and ribs (200-250) and hard wood for chicken (275-375). Every smoker has a temp it likes to run based on the design and air flow. Mine settles in @ 220 on fuit wood and 325 on hardwood and I never touch the intake or exhaust (both wide open).
IF my temps have dipped I leave the ash door open until the new log ignites and burns a little before I close the door. If the temps spike, I raise the main door and let a little heat out. I usually get a bout a 20 degree drop each time the main door is opened.
Oklahoma Joe Longhorn ~ Smokin Tex 1500 CXLD ~ 24" Lone Star Grillz Vertical (on loan)