Pork Butt Cook Time?

[Pa_BBQ]

I know it's done when it's done but going to cook 2 8lb butts today while at work on my Kamado Joe II and fireboard and not sure when to put them on.
When cooking on my Shirley, usually done in 5 hours or so, but she likes to run around 300.

 

[patrickd26]

I have a Primo (ceramic/kamado). I plan for about 8 hours at 275. Also, I don't add much for wood. Maybe 2 or 3 small chunks throughout the cook. I get solid results every time. I also use a fireboard with a pit viper fan from Digi-Q.