In regards that pork shoulder (aka pork butt). Some controvery on what temp I've seen mention of everything from 180 to 205. I also shoot for an internal of 205
I shoot at 190. From there, I "squeeze" the butt with my tongs to test the tenderness. If it flexs and changes shape with the "squeeze" and it looks like it is pullable. Then off into the cooler it goes. If not, then I wait for 195, and so on and so on.