Here's what the gauge looks like my 2001 2500hd, and you can see what it indicates as being too hot, this being said, the hottest I've ever seen it is about 180 in the summer, unloaded.
Directions. 1  In a Dutch oven, cook ground beef and onion until meat is no longer pink and onion is tender; drain. 2  Add the next eight ingredients; bring to a boil. 3  Reduce heat; cover and simmer for 1 hour, stirring occasionally. 4  Remove the bay leaf. 5  Serve with spaghetti. 6  Garnish with oregano if desired.
Step 1, Boil and drain shells according to package directions. Step 2, Rinse to cool so the shells can be handled. Step 3, Blend cheese mixture together with a spoon until well blended. Step 4, Pour 1/3 to 1/2 of spaghetti sauce in bottom of a 9 x 13 inch pan. Step 5, Stuff shells with cheese mixture and arrange in pan.