You may use the intact muscle rule and apply this chart if you don't pierce the meat with a temp probe prior to the outside going over 140F for 12 minutes, or 140F for 30 minutes to make sure of 1/2 inch penetration. Sterilize the probe and insert after time temp duration above.
Then cook and hold to time temp duration below depending on where you want it to end up. I find pork loin is best pulled at about 155 F or so and allowed to rest 15 minutes tented in foil so it rises through about 162 F.
Whole Roasts
# (beef,pork, ham, corned beef,lamb, venison, bison)
Minimum Internal Temp
(
°F)Holding Time* at Specified Temperature
130 121 minutes
132 77 minutes
134 47 minutes
136 32 minutes
138 19 minutes
140 12 minutes
142 8 minutes
144 5 minutes
145 3 minutes
Above 145F you are good at any temp after 15 seconds at the temp.