Checking Ford 9 inch differential play

I noticed you recommended the poster asking how to depressurize his car’s fuel system to remove the fuel pump relay? Is that the correct method?

Got around to measuring rear wheel play, at outer edge of 27" diameter tire. Brakes released, other wheel on ground, in Park. 1 inch of play. Wheel circumference = pi * d = 85 inches. 1 inch out of 85 inches = 4.2 degrees of play.