Maria, welcome to Community. Your question illustrates the difficulties experienced with many SV recipes. They co-mingle conventional cooking thinking in recipes, most of which is wrong, with the precise nature of SV cooking.
To answer your pork tenderloin cooking question, always use the lesser dimension, 2-inches. Using Table 5.1 in Douglas Baldwin's excellent work you will discover that at 140F cooking time will be 2 1/2 hours. That will result in medium doneness, tender and juicy. Cooking temperature can be adjusted according to your preferred degree of doneness, Medium-rare (130F) to well-done (160F). Your cooking time can be extended to 4 hours to add tenderness.
Here's your link:
Jason Logsdon developed a fairly useful ruler based on cook time tables developed by Nathan Myhrvold and Douglas Baldwin.
Here's the link: