The <60" horiz. distance measurement from ball to bumper tip is only the clearance so your bumper will not hit the trailer when turning. With a newer 4X4 Tundra you have really high bed rails, You will more than likely need a lifted trailer and raised hitch.
If you have a 2010 trailer or newer with bolted on axle
a lift is fairly easy and inexpensive. If you have an older (Mid 80s) 5er with bent neck tongue, besides an axle
lift you may need to also modify the tongue to get the needed height in addition to raising the hitch.
Put a 2x4 across your bed rails and measure to the ground. Then level the trailer and measure from the upper deck lower fiberglass edge to the ground. The trailer need to be at least 6-8 higher than your bed rails and your hitch needs to be adjusted to maintain this distance.
Do you have a picture of your trailer setting level and what year is your trailer?