Here's a summary of the data:
The purpose of the test was to allow me to obtain some data that would allow me to select a desired time (just like my need for 6 hours today!), and then determine what the temperature should be held at for the meat's internal temperature. The data was obtained from a thermocouple inserted into the middle of a controlled cross-section of pork shoulder (boneless). It was then cooked in a Souse Vide machine (in a bag to keep out the water), at a controlled temperature (+/- 2 degrees) until the meat (in my subjective judgement) was pullable.
The test was to determine the length of time necessary to produce pullable meat if the internal temperature of the meat was held at a controlled constant temperature. The time to cook at temperature is started when the meat reaches the stated test temperature. It does not include the time to bring the meat up to that controlled temperature. That's very important to understand. Since bigger pieces of meat require longer to come up to temperature, that time would vary depending on the size and shape of your meat. However, once it's up to the controlled temperature, the question was - how long does it need to remain at this temperature before it becomes pullable (and that's subjective based on what I consider pullable).
So here is the summary of the data.
Controlled Temperature Time at Temperature to become pullable
145 dF 41 hours
155 dF 31 hours
165 dF 14.5 hours
175 dF bad data - temperature probe pulled out
185 dF 5.25 hours
195 dF 2 hours
I did a scatter-plot of the times, and they are predictable.