It is done when it is done.
Almost every peice cooks up different.
There is a great tutorial on our site.
As to time--it is temp dependent.
At 210-225, maybe about 2hrs/lb.
At 250-275, maybe about 1.5hrs/lb.
At 300 +, maybe 1hr/lb.
All those are "Guesstimates" and will vary all over the place.
I suggest you read the thread above.
"Flirtin' with Disaster" BBQ Team (RETIRED)
FBA and KCBS Cook and Judge.
Former owner of a WSM, a Smokey Joe, a Charbroil Commercial gasser (junk), the legendary "StudeDera", a Fast Eddy PG500, and Sherman.
Now cooking with a Yoder YS640
Proud Pellet guy cooking on real wood.