john i know the big 3 have plastic crates but i aint sure where to get them from..
i've always just took a good skid and then some 4x4s and nailed them onto the skid to get the engine to sit straight and keep it from going any where then strap it down with metal straps used in shipping and built a side and top.
PM Jim Monson. He told me a while ago who sells the plastic crates but I can't remember who.
A cheaper way. All you need is a engine cradle to hold the motor as its bolted to a wood pallet. Get a 40" x 40" wood pallet, and go to Home Depot or Lowes and get 5-pieces of 1/2" plywood cut the same size and some 2" wood screws. I just did it. Took about 1-hr.
I use Scribner for all of my tranny shipping crates. They are a bit pricey for my taste... but nothing good is cheap! Never had an issue with their products.
We have shipped our engine to Schmidt's shop in Indiana from Tx using the method Suicidal posted... worked like a charm there and back in one piece no worries. If it is a fresh engine just make sure it is wrapped very well in cellophane before it goes into the crate.