Charlie:
The passenger car damper measures 6.250 diameter. I don't know if your truck has a different size damper or not. At any rate, your damper should have some degree marks on it, maybe a total of 10 degrees, some have more. Anyway, you can use a pair of dividers, or even a grade schooler's compass, set it to match the degree marks on your damper and step off your desired marks.
John in Selma, IN
John - "The Hoosier Hurricane"
