First step is to make sure the body is centered with the tires, not the frame.
These are the same pictures, but notice the circle drawn around the tape on the tire.
The best way to center the body with the tires is to place a piece of masking tape on the tire in the same place on each side. If you look close you can see this small piece of tape on the tire.
Next find the center and measure 15 9/16 inches for the center and make a mark.
The SB manual says to measure 16 inches from the center but, check your bumper.
Mine was only 15 9/16 inches from the center.
Then my grandson, Clint, drilled up through the frame. All the way into the trunk. He is wearing leathers for protection from the hot metal.
Then using the brackets and a guide, cut out a hole big enough to clear the brackets. Remember this will be covered by carpet later.
After the hole is cut out the brackets are installed. Using the holes in the top bracket drill a hole back through the body.
Then measure 2 1/4 inches, be sure to measure your bumper, down for the bottom hole.
I used 4 chrome spacers, 1 1/4 inches long and 4 spacers chrome spacers 4 inches long and 4 bolts 7/16 x 6 inches.
The short spacers go between the most rear bumper and the tubular bumper part.
Then the long spacers go between the tubular bumper part and the bracket.
This is what is looks like after assembled. The red color brackets that are mounted where the tail lights go are for the body rotisserie that will be used later.
Now that the bumper has been installed, my wife said she didn't like it, so off it came. Easy enough.