Chevrolet Silverado Classic 2007 Owner's Manual page 449

If you use a step-bumper hitch, the bumper could
be damaged in sharp turns. Make sure there is
ample room when turning to avoid contact between
the trailer and the bumper.
If you will be pulling a trailer that, when loaded,
will weigh more than 5,000 lbs (2 270 kg) be sure
to use a properly mounted weight-distributing
hitch and sway control of the proper size.
This equipment is very important for proper vehicle
loading and good handling when driving. Always
use a sway control if the trailer will weigh
more than these limits. You can ask a hitch dealer
about sway controls.
Fifth Wheel and Gooseneck Trailering
Notice: Pulling a fifth-wheel trailer with a
vehicle that is equipped with the SS trim
package could damage the vehicle. Do not pull
a fifth-wheel trailer with a vehicle equipped
with the SS trim package.
Fifth wheel and gooseneck trailers can be used
with many pickup models. These trailers place
a larger percentage of the weight (kingpin weight)
on the tow vehicle than conventional trailers.
Make sure this weight does not cause the vehicle
to exceed GAWR or GVWR.
Fifth wheel or gooseneck kingpin weight should be
15 to 25 percent of the trailer weight up to the
maximum amount specified in the trailering chart
for your vehicle. See "Weight of the Trailer" in
this section for more information.
The hitch should be located in the pickup bed so
that it's centerline is over or slightly in front of
the rear axle. Take care that it is not so far forward
that it will contact the back of the cab in sharp
turns. This is especially important for short
box pickups. Trailer pin box extensions and sliding
fifth wheel hitch assemblies can help this
condition. There should be at least six inches of
clearance between the top of the pickup box
and the bottom of the trailer shelf that extends
over the box.
Make sure the hitch is attached to the tow vehicle
frame rails. Do not use the pickup box for support.
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