I recently shipped this 'Crate' from Milwaukee to Hartford,CT, via Forward Air Freight. I made the 24-inch cube to fit around the CB750-K0 motor out of used cedar planks taken from an outdoor deck. It is completely held together with decking screws. After I made the base 'pallet' I placed the motor on two side-rails to raise the sump. I then placed a used motor-mount bolt through the rear motor mount and zip-tied each end of the bolt to the pallet. I was careful to locate the motor so that the sides would not rub and the exhaust spigot would be very close to the crossing boards. I covered the motor in 'bubble-wrap' and used some old magazines to wedge between the boards and the ends of the crankshaft covers and at the top near the valve-cover.
The total package weighed about 240 lbs. and cost about $245. I delivered it to the shipping terminal on a Friday afternoon and they unloaded it from my van with a fork-lift and the crate was placed on a scale. After filling out some short paperwork, I paid for the shipping with a money-order that I acquired at a gas-station a few blocks from the terminal. The 'crate' arrived at its destination on the following Wednesday without damage. Forward Air is a less-than-load trucking company with terminals at or near all major US airports.
I'm posting this for basic information and hope it will help someone. By using screws, the recipient can easily dismantle the crate. I have also shipped complete bikes via Forward Air with good success.