There is no way that butt is almost done. A 9 pounder at the temps you are running should take 10-12 hours if not more. Something has to be out of wack..
What pit are you using and what are you using to monitor cooker temps?
18" OTS, 22" OTG, SJ Silver, Vintage 1981 Coleman Bullet, PBC, UDS, QMaster Senior ATC