The crossmember should be sitting level with the ground when the truck is at ride height. Bobco has found that with the frame sitting level the crossmember should be set approximately 2 to 3 degrees lower in rear than the front to duplicate the most common installation when using small front tires and larger rears. Most people use a 25- to 26-inch tall front tire and 28- to 29-inch tall rear tire. Measure your wheel and tire combinations and base your ride height and frame angle on that. If you're using the same size tire all around, place the crossmember level. Mike determined this angle by placing a magnetic angle finder (protractor) on the top of the center of the crossmember.