I do not even know what the temperature was since I do not use a thermometer when I do it. I closed all the vents as soon as I was done to try to conserve some charcoal.
I've done legs on the WSM. Bout 225-250, hour and a half to two and a half. Depending on how thick the legs are. They were very succulent indeed! But I've found that if you go hotter, there is a much finer line between crispy and dried out and crispy. And hotter is much faster. Just thinking about it makes me hungry.
About a chimney of unlit followed by 3/4 chimney of lit. Empty foiled pan with an airspace, leave vents wide open and you should be well above 325 measured at the top vent.
Usually takes 45-60 mins for me on my 18.5" in my backyard.
I have a few of those Bayou classic legs & wings racks which work really well on the WSM.
Another thing that will make them taste ten times better is bull the skin all the way down but not off careful not to rip it season directly to meat then pull skin back up and season skin as we'll absolutely makes one heck of a difference
When the drums are about done you can take off the middle piece of the WSM and put the grate directly above the coals. This will crisp them up nicely. Just be careful to not burn them.